Table of Content

20 August 2011, Volume 33 Issue 4

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地质勘探

Key Technologies of Seismic Exploration in Lithologic Gas Reservoir of WestSichuan

DUAN Wen-shen; WU Chao-rong

2011, 33(4):  1-6.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.001

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The 3D seismic exploration is the key technologies to support lithologic gas reservoir prediction and well
deployment in west Sichuan. Through the research of seismic acquisition， processing， interpretation， reservoir and
fluid prediction of Jurassic lithologic gas reservoir exploration in west Sichuan depression， a suit of key technology
is summed up， that is， in seismic data acquisition， the key is good design and quality control； in processing， the key
is to preserve amplitude processing； in interpretation， the key is to insist“whole， automatically， fine” three basic
criteria； the reservoir prediction relies on the amplitude information， and flow forecast makes full use of parameters
of frequency and absorption. These technologies are carried out in 10 districts， deploying more than 60 exploration
anddevelopmentwells， andsubmittingprovenreservesofabout500billioncubic. Furthermore， thesetechnologies
arealsoanimportantreferencefortheexplorationofdenseclasticrockgasreservoirthatwidelydistributedinChina.

The Tectonic Controls on the Distribution of Marine Oil and Gas in the AdjacentAreas of Xuefeng Mountain

YANG Xin;;LIU Xing-wang;WANG Ya-dong;LIU Yan-hong;ZHENG Jian-jing

2011, 33(4):  7-12. 

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Based on determining the property of the tectonic activity of the Xuefeng Mountain， according to the
original petroleum geology condition， post-destruction of oil and gas and sub-generating characteristics of reser-
voirs in western Hunan and Hubei， and central Hunan regions， this paper explores the tectonic controls of Xuefeng
Mountain Activities on the distribution of marine oil and gas in adjacent areas. Studies show that the Caledonian
movement and Yansian movement were the most powerful two intracontinental orogenic events in the Xuefeng
Mountain region， and the regional disparity of tectonic deformation has led to the differences of geology charac-
teristics and distribution of marine oil and gas on both sides. The maturity of source rocks of lower assemblage in
western Hunan and Hubei provinces are high over-mature， and the component is mainly dry gas， and they mainly
gather in structural-lithologic compound traps， where the plugging condition are better in synclinorium. The marine
oil and gas of the Hunan regions gather in upper assemblage， and the source rocks are mature-over-mature. The
ancient anticline under Longtan Formation coal-bearing cap rock and the sub-anticline within adjacent syncline are
more favorable for oil and gas sub-aggregation.

LIU Tai-xun， ZHA Ming， WU Kong-you

LIU Tai-xun;ZHA Ming;WU Kong-you

2011, 33(4):  13-19.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.003

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Many stratigraphic reservoirs with unconformity have been found in Wuxia area of the northwestern edge
of Junggar Basin. It is important to study the role of the unconformity in the process of hydrocarbon accumulation.
On the basis of 3D geological model and analysis of Erosion Thickness， the formation of unconformity and burial
history of this area were studied， and the 3D dynamic system was simulated. Simulations show that the three sets of
source rock reach maturity and expulse hydrocarbon at different ages in Wuxia area. The source rocks in Jiamuhe
formation reach maturity at middle Permian and Late Permian Epoch. The source rocks in Fengcheng formation
reachmaturityatLateTraissicEpoch. ThesourcerocksinLowerWu’erheFormationbegintogeneratehydrocarbon
at Jurassic Period. The unconformity conduit simulation shows that the role of unconformity near the source rock
is more important than that far from the source rock in the process of hydrocarbon accumulation， and that oil and
gas migrate along the ridge in the weathering-cracked loess horizon and basal conglomerate. It is the predominant
pathways for oil and gas migration. The lateral migration distance in along the ridge in the weathering-cracked loess
horizon is shorter than that in basal conglomerate. Oil and gas mostly break through thin clay area and migrate to
near horizon in the same unconformity. Unconformity is not only the hydrocarbon passage systems but also the oil
and gas accumulation place. The distribution of Oil and gas pool is relevant to the block of the unconformity. The
Oil and gas pool distribute at the block of unconformity.

Characteristics and Distribution of Reef Group in Upper Triassic in WesternSichuan

YANG Rong-jun;LIU Shu-gen;WU Xi-chun;SUN Wei

2011, 33(4):  20-26.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.004

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Siliceous sponge reefs have been revealed in the upper Triassic Ma’antang Formation in western Sichuan.
The lithology， fossils， distribution and controlling factors of those reefs have been researched， but can be studied
in a deep-going way. Comparing those reefs and the upper Jurassic siliceous reefs in Europe， it is considered that a
series of sponge and coral may exist in the western Sichuan， according to the evolution of the global siliceous reefs
andthecolliculusupliftintheseismicprofiles. Thesiliceousreefsdevelopedintherelativelydeepwaterandthelow
energy environment， which had been exposed by late tectonic movements. While the predicted reefs may develop
in the shallow water and relatively high energy environment， which have been deeply buried in the depression of the
western Sichuan Basin. And the distribution of the siliceous reefs is obviously influenced by the Qinlin Old land，
whose size turned smaller northwardly. This is of significant for understanding the transfer process frome the marine
carbonate to the marine clastic rock and the oil exploration direction in the Ma’antang Formation.

The Diagenetic Model for Sandstone Calcareous Layers of Zhujiang Formationin Qionghai Bulge

CHEN Jin-ding;ZHOU Xiao-lin;ZHONG Guo-lou;ZHENG Qi-yuan;HU Sheng-hui

2011, 33(4):  27-32.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.005

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Though predecessors have done some studies of the calcareous layers (Namely the sandstones which is
rich in calcite cements and bioclasts， called calcareous layers for short， hereafter. ) that distribute in the Zhujiang
formation reservoir of Qionghai Bulge， Beginning with studying the relationship between diagenism and sequence
stratigraphy， this paper compares the calcareous layers in section 1 with section 2， Zhujiang Formation of WC13-
1/13-2oilfield， andanalyzeshowthedepositionalsystemcontrolsmineralionsandthenfurtherstudythedistribution
law of calcareous layers units the diagenetic evolution of stones. The studies show that the formation of Calcareous
layers of Zhujiang Formation has the same master control factor， which is depositional system tract. And from
section 2 to section1， the diagenesim has certain continuance and discontinuity.

The Comparison Methods of Thin Sandbody of Meandering Facies in XintanOilfield

CUI Wei-dong

2011, 33(4):  33-38.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.006

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Division and comparison of sand body are important contents in field development. Sand body compar-
ison is difficult because Ng5， Ng6 of Kengdong18+32 is meandering stream. This article depicts the sedimentation
type and feature of meandering stream in Kengdong18+32. The layer position is divided by means of marker bed
and assisting marker bed. Time cell is determined by the way of sedimentation cycle and uniform thickness section，
and defined with height unite area analysis. Finally， sand body comparison scheme is built. The article considers
feature of meandering stream sufficiently. It also interprets the effect of differential compaction on cut plane， sand
bed compare graph of filled and normal river channel， superimpose or lower cutting comparison of thick sand and
thin sand body from the view of the sedimentation feature of meandering stream. Then the article builds up the way
of sand body comparison of meandering stream. Fine sand body comparison and division provide reliable geology
foundation for further geology research， numerical simulation and analysis of remaining oil.

Fracture Prediction of Changxing Formation in Huanglongchang Structure

WANG Shi-lin;QIN Qi-rong;DONG Hai-ying;SU Pei-dong

2011, 33(4):  39-43.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.007

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ReefreservoiristhemainreservoirtypeofChangxingFormationinHuanglongStructure， butthedynamic
data analysis suggests that different production wells vary dramatically in productivity. Research shows that the
productionofsinglewellismainlyaffectedbyfractures. Therefore， predictionsonfracturesofChangxingFormation
in Huanglong Structure can better guide well pattern and development. By analyzing the tectonic origin and power
source of the study area， this paper builds up the structure formation models of the study area. By combining
petroleum geology， structural geology， rock mechanics and a variety of production materials and by applying two-
dimensional numerical simulation of paleo-tectonic stress field， the cracking degree of the rock mass is predicted.
Then the failure approach index is calculated and the relation between fracture development and the cracking degree
oftherockmassisdefined， whichhelpstodeterminethedevelopmentlevelsoffracturesandmakesacomprehensive
prediction of fracture development， fracture types and attitude. Vector direction of principal stress in early and late
stages in Huanglong Chang classifies the fracture development into 2 stages， 4 grades and 6 categories.

Diagenesis Characteristics of the Chang8-Chang 6 Member of YanchangFormation in Yichuan—Xunyi Area， Ordos Basin

2011, 33(4):  44-52.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.008

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Through the core observation， thin section analysis， scanning electron microscopy， cathode lumines-
cence， carbon and oxygen isotopes， clay minerals X-ray diffraction and temperature of fluid inclusions， etc， the
chang6-chang8 member of Yangchang formation is studied and the results show that it consists mainly of gray
feldspathic sandstone and lithic feldspathic sandstone， which experienced a series of diagenesis like mechanical
compaction， cementation， dissolution. X diffraction analysis shows that clay minerals are mainly illite， illite /
smectite mixed layer， chlorite， and vitrinite reflectance Rotest between 1.03∼1.31， combined with inclusion tem-
perature and diagenetic phenomena comprehensive study indicates that the main sandstone reservoir area come into
the late diagenetic A2 sub-period， some of which have reached the early period of late diagenesis B. Besides， the
diageneticsequenceisdetermined． Basedonthediagenesisanalysis， theresearchshowsthattheporosityofChang8-
Chang6 member respectively loss 23.82% and 25.65% because of compaction， and 3.99% and 3.31% because of
cementation， and that porosity are added by 0.84% and 0.83% respectively due to dissolution． The compaction
and cementation are major factors in deterioration of physical properties， but the reservoir sandstones， which have
chlorite central side of the weak growth and early secondary quartz， play a significant role in the preservation of
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primary porosity. It is pointed out that the favorable diagenetic facies study can effectively guide the identification
and prediction of reservoir， which is useful for the oil and gas exploration．

The Cambrian Sequence Stratigraphy Framework andSource-Reservoir—Caprock Association of Bachu Uplift in Tarim Basin

YANG Yong-jian;;LIU Jia-duo;TIAN Jing-chun;MENG Wan-bin;ZHU He

2011, 33(4):  53-58.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.009

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Based on comprehensive analysis of the outcrops， wells data， seismic explanation data， and guided with
sequence stratigraphy theory， the sequence stratigraphy of Bachu Uplift Cambrian is divided into fourteen 3rd-
order sequences and three 2nd-order sequences which belong to type I sequence and were constituted by TST and
HST. In the Cambrian period， the sedimentary environment is mainly showed as alternating deposition of restricted
platform-evaporation platform， the water depth is mainly showed as the northwestern margin is relatively deep and
the southeast is shallow. On the basis of above， this paper discusses the characteristics of source-reservoir-cap rock
and its rule of combination on the basis of sequences stratigraphic framework， the results show that there are 1 set
of source rock， 3 sets of reservoir and 2 sets of cap developed in the Cambrian in the study area. The source rock
is SS1 HST， reservoirs are SS1 HST， SS2 TST， SS3 TST and HST， caps are SS1 HST， SS2 HST. They combined
into 2 sets of good source-reservoir-caprock assemblages. In addition， most dolomites in the outcrops or in the drill
core have been changed by hydrothermal， and the greater intensity of hydrothermal alteration， the more developed
dissolution pores. Therefore， in some of the places where intense tectonic activities happened， hydrothermal then
began to change the rock by migration. At last， it formed good reservoirs.

Logging Data Application in Sanding Prediction in Nanpu 35–2 Oilfield

LIANG Dan;;ZENG Xiang-lin;FANG Mao-jun;

2011, 33(4):  59-63.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.010

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Analyzing the sanding mechanism in Minghuazhen Formation， Nanpu 35–2 Oilfield， the logging data
are used to calculate the rock mechanical parameters， such as cohesion， angle of internal friction， elastic modulus，
Poisson ratio and maximum level principal stress. Then the methods of sand factor and Schlumberger are applied
to forecast sanding and calculate the critical drawdown pressure. Based on the sanding forecast method and the
model of critical drawdown pressure， the reservoir sand production index profile and the critical drawdown pressure
profile are compiled. Calculation results show that the possibility of Minghuazhen Formation sand production is
high. Research results provide quantitative basis for defining sand production in this block and the nearby， and
guidance for reasonable formation of oil well work system.

Seismic Random Noise Attenuation via Monte Carlo Estimator in CurveletDomain

ZHANG Heng-lei;LIU Tian-you

2011, 33(4):  64-68.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.011

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Fortherandomnoisesuppressinginseismicrecordswithlowsignaltonoiseratio， traditionalmethodswill
harm the signal components. The paper thinks curvelet transform can separate the random noise using multi-scale
and multi-direction. The authors apply Monte Carlo estimator to compute the noise level and design a non-linear
thresholding function to remove the random noise coefficients， so the useful signal will be recovered. Applications
on both synthetic data and actual seismic data from Dabashan area show that the new method eliminates the noise
portion of the signal more efficiently and retains a greater amount of geologic data. The quality and consecutive of
seismic event are better as well as the quality of section is improved obviously， and it overcomes the drawback that
the conventional filtering approach may affect the effective wave when suppressing noise.

Method of Gas Saturation Prediction by Elastic Modules

WANG Lei;WANG Xue-qin;WU Sheng;CAO Rui

2011, 33(4):  69-72.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.012

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The determination of gas saturation based on elastic modulus of formation enriches the methods of in-
terpreting and evaluating reservoir， improves the interpretation accuracy of gas saturation which is a very important
parameter. The elastic modulus can be determined by the velocities of compression and shear waves obtained from
array sonic logging as well as the information of density. According to Gassmann equation which describes the
relationship between the bulk modulus and shear modulus in a low frequency situation， an equation is established
between the gas saturation and bulk modulus as well as shear modulus in cases of rock matrix， gas saturated and
water saturated separately， thus gas saturation can be calculated. The processing software based on the model is
developed. The examples of Sichuan central field show that the methods are sufficiently accurate and reliable.

Study on Deep Subtle Structure of Jiyang Depression and Its ExplorationSignificance

XIA Bin;;WEI Hai-quan;;;YUAN Ya-juan;;ZHANG Yong-hui;;;WAN Zhi-feng

2011, 33(4):  73-77.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.013

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Based on the complexity of the structure， the paper presents the concept of subtle structure. It refers
to those whose characteristics and evolution history can not be identified owning to the limitation of exploration
technology and the complexity of the structure itself. The study of the subtle structure should be based on the iden-
tification of its interface and signs of deformation， and focused on analysis of the stratigraphic structure guaranteed
by advanced tectonic thinking and technological means. Lots of subtle structural styles form in the deep Jiyang De-
pression. These styles are strike slip fault zone， deep Jiyang development of large-scale strike-slip faults， inversion
structures， structural transform zone， diapir structure belt， buried hill structure and buried fault， i. e.. The explo-
ration for buried hill can be explored along strike-slip fault. Identification of hidden structural styles are guidance
and reference for expanding new areas of deep oil and gas exploration， optimization and evaluation of favorable oil
and gas accumulation zones， and further oil and gas comprehensive geological study.

The Study of Fracture Characteristics and Causes at Feixianguan Formation inXuanhan Area of Eastern Sichuan

TANG Hai;WANG Quan-lin;PENG Xin-ling;LI Li;HUANG De-ming

2011, 33(4):  78-84.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.014

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The fracture characteristics of Feixianguan Formation in Xuanhan area were analyzed by whole diameter
core observation and thin section analysis information， and the growth state and longitudinal distribution of frac-
tures were studied from conventional logging data at every well； Based on ahead of analysis， fracture genesis was
researched deeply through combined with geological structures in east of Sichuan. The results show that vertical
tectonic， horizontal， diagonal and diagenesis fractures mainly develop at the lower of Feixianguan Formation； there
are two kinds of fracture that is tectonic and non-tectonic， and tectonic fracture is associated with faults， drape and
weak deformation areas， which has three kinds of mechanical causes， which are shear fractures， expansion fractures
and tensile fractures. Non-tectonic fractures can be divided into four kinds， which are diagenetic fracture， corrosion
fracture， shrinkage fracture， supergene fracture. The production practice indicates that any fracture in carbonate
reservoirs is important in both storage space and the flow channel.

石油与天然气工程

Jetting Pressure Field in Formation Cavities during Hydrajet Fracturing

QU Hai;;LI Gen-sheng;HUANG Zhong-wei;LIU Zu-lin;SHI Ming-jie

2011, 33(4):  85-88.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.015

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Hydrajet-fractruing is a new stimulation technique in oilfield. It is very necessary to study jet parameters.
Based on the experiments and computational method of fluid dynamics， the jet pressure field around a cavity has
been calculated. The velocity and pressure in cavity is obtained by fluid simulation. The following parameters were
analyzed： nozzle space location， the number of jet， cavity shape， differential pressure and nozzle diameter. The
result shows that the pressure in cavity will increase with the drop of nozzle pressure and the increase of nozzle
diameter. The jetting stream creates the same pressure in the cavities in spite of their different shapes. The location
and the number of nozzle have no influence to the cavity pressure. The conclusions can provide scientific basis for
the oilfield performance of hydrajet-fracturing.

A Development Planning Study on Thermal-Chemical Combined Flooding forHeavy Oil

CHEN Min-feng;FAN Ying-bin;ZHAO Dong-feng;WANG Zhen

2011, 33(4):  89-95.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.016

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The thermal-surfactant combined flooding is an effective EOR technique for heavy oil reservoirs， which
has been applied in several oilfields for pilot tests. A theoretical study on this technique is conducted by means
of analytical analysis and numerical simulation. A comparatively complete thermal-chemical flooding mathematic
model is built based on the dominant physical and chemical phenomena occurred during this combined flooding，
and a 3D three-phase simulator is developed correspondingly. To improve the economic benefits of such a combined
flooding， prediction models of different development stages are set up by means of injector-producer correlationship
analysis and numerical reservoir simulation. Then， the non-linear programming theory is employed to perform
integrated programming for heavy oil reservoirs in the situation where steam flooding is initially adopted and a
combined flooding is adopted at later stages. The self-adapting genetic algorithm is used for model solution， the
results of which indicate that a programmed combined flooding can lead to better economic benefits.

Exploration on Reservoir Heterogeneity Characterization in ReservoirNumerical Modeling of Multi-Substratum Sandstone Reservoir

GENG Zhan-li;SUN Fu-jie;TIAN Ji

2011, 33(4):  96-100.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.017

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A new method on reservoir heterogeneity characterization in reservoir numerical modeling is presented
based on end point scaling of pseudo-relative permeability. The relative permeabilities of each point of well log
around accuracy rating are first calculated from the relative permeability， which arises from core flooding tests.
Thus the pseudo relative permeability of a substratum consisting of many well log points around accuracy rating is
obtained. The function relation between pseudo relative permeability of a substratum and relative permeability from
labs is studied， which stimulated the presentation of relative permeabilities of all cells among wells in reservoir nu-
merical modeling. The amount of relative permeability of all cells is determined from reservoir numerical simulator.
It has been proved that flow characteristic of oil-water two phases in layered sandstone reservoir could be modeling
more accurately based on the above method.

Analysis on Configuration of Multi-Lateral Well for Coalbed Methane

ZHANG Hui;YU Yang;GAO De-li;ZHENG Jiang-li

2011, 33(4):  101-106.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.018

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The third phase of coal-bed gas exploitation lasts long time， so stable seepage laws of this phase should
be studied. Pseudo pressure function is adopted to resolve this problem by J. P. Seidle. The pressure distribution
equations in the formation of multi-lateral well for coalbed methane are constructed on the basis of pressure super-
position and mirror image reflection theory. Pressure drop influence on the deliverability is considered. By coupling
wellbore flow and reservoir stable seepage flow， the deliverability calculation model and its solution method for
multi-lateral well are established. Rules of influence on deliverability of multi-lateral well for coalbed methane is
analyzed.

Study on Production Performance of Fractured Well Under the Condition ofVariable Conductivity

JIAO Chun-yan;HE Shun-li;ZHANG Hai-jie;LIU Hua-xun

2011, 33(4):  107-110.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.019

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A large number of experimental studies have shown that long-term flow conductivity of artificial fracture
changes over time. So this paper establishes mathematical model of percolation in the condition that the long-term
flow conductivity of the artificial fracture alters over time. By numerical simulation， this paper states about the
impacts of change of the long term flow conductivity on the production and flow field. The results show that the
loss of the flow conductivity will lead more formation fluid to the bottom of well through the fracture near the
bottom， which makes the flow field in the fracture reasonable and slows down the decreases of productivity. When
other conditions are same， the longer the fracture is， the more impact the lost of the flow conductivity has on the
productivity.

A New Method of Determining the Optimum Performation Intervals of Wells inReservoirs with Bottom Water and Gas Cap

HE Wei;HUANG Quan-hua;GUAN Lin

2011, 33(4):  111-115.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.020

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It is highly difficult to exploit a well producing from reservoir with bottom water and gas cap， because
it has characteristics of both gas cap reservoirs and bottom-water reservoirs. These reservoirs mainly produce crude
oil. During the exploitation， gas breakthrough and then bottom water coning usually take place， which shortens
period of stabilized production and leads to quick declination of production rate， and the oil recovery ratio generally
turns out to be low. But if there is non-penetrative barriers between gas/oil contact or oil/water contact of reservoir，
it will slow down the speed of gas breakthrough or bottom water coning effectively， and the period of stabilized
production for wells will be extended. But the demands of oilfield development can’t be satisfied because at present
methods of determining perforation intervals of wells in gas cap and bottom-water reservoirs fail to take all factors
into consideration or just use approximation method with plate. Besides， the influence of barriers in reservoir is
always neglected. An optimization method， which has been verified in oilfield producing， is offered to determine
optimum perforation intervals of wells in gas cap and bottom-water reservoirs.

Numerical Simulation of“Gel Dam” In-Depth Fluid Diversion Technique inHorizontal well

LÜJing;LIU Yu-zhang;WANG Jia-lu;WANG Qiang;LI Yi-kun

2011, 33(4):  116-120.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.021

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The purpose of this paper is to study the sensible factors of“gel dam” in-depth fluid diversion technique
by numerical simulation. By using the ECLIPSE commercial simulator， targeted at two-layer 2D model， five-layer
2D model and one five-layer five-spot pattern model， we study the sensible factors for“gel dam” in-depth fluid
diversion technique， such as the location， height and number of the“gel dam” . The results indicate that the“gel
dam” in-depth fluid diversion technique is an effective EOR method. When the“gel dam” or the horizontal well is
in the middle of the well spacing or near to the production well， there will have a higher effectiveness. The higher
the“gel dams” are， more effective the water flooding is. If many gel dams with height up to more than 40% of
reservoir thickness are joint together， there will be a better EOR effectiveness. The sooner the“gel dam” measure
has be taken， the more volumetric sweep efficiency can be increased. Even if the“gel dams” measure has been
taken at very high water cut， the recovery of the reservoir can also increase. If the“gel dam” measure is adopted
and combined with water shutoff， the oil recovery of the thick positive rhythm reservoir can be enhanced in a long
time. The conclusions provide a valuable guidance for field trial.

Efficient Fracturing Technique Research and Application in Natural FracturesReservoir

WANG Feng;

2011, 33(4):  121-124.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.022

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Natural fractures in reservoir lead to large amount of the fracturing liquid filtered， the complicate expand-
ing laws of artificial fractures， and higher probability of sand’s walling up. Aiming at Qianbei-Daqingzijing region
natural fractures growth degree and pollution of reservoir， efficiently fracturing technique research and application
in natural fractures reservoir are carried out. According to analysis of natural fracture distribution law and the rela-
tionship between two horizontal principle stress difference and fracture extension net pressure， technology measure
and conditions of supporting natural fractures are proposed. The injury factors of fracturing process are comprehen-
sively analyzed. The gel breaker， which can effectively degrade the middle-high temperature enzyme in fracturing
fluidresidues， isdeveloped. Upontheapplicationoftheresearchresultsin16wellsofQianbei-Daqingzijingregion，
the stimulation effect is obvious， which provides a new way of fracturing in natural fracture reservoir.

Weak Polymer Gels Flooding Experiment in Low Permeability and High SalinityOil Reservoir

YU Guang-ming;;GAO Chun-ning;;WU Ping-cang;;LI Wen-hong;;LI Ai-qin;

2011, 33(4):  125-129.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.023

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Based on the low permeability and high salinity oil reservoirs of Jurassic， this paper summarizes the
experiences and lessons of polymer flooding experiments in recent years. According to the present technology in
weak polymer gel flooding at home and abroad， and based on the geologic reservoir features and current status of
exploitation， a weak polymer gel flooding system which meet the situation of low permeability and high salinity oil
reservoir of Jurassic is developed， and the system performes well in the field experiment. The results showed that
weak polymer gel flooding system is suitable for low permeability and high salinity oil reservoirs； it can slow down
the descending， reduce the water ratio and enhanced oil recovery.

A New Method of Performance Prediction for Multi-Layer Reservoir ProfileControl

FENG Qi-hong;;ZHANG An-gang;JIANG Han-qiao

2011, 33(4):  130-134.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.024

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In view of the exiting problems in the performance prediction for profile control， a new performance
prediction model for multi-layer reservoir profile control is established. Combining profile control mechanism，
an ideal geological model of“multi-oil layers” containing profile control layers and non- profile control layers is
applied to simplify real layers. Firstly， according to the change in plugging rate， the injectivity index of each layers
is evaluated， and water absorption of each layers is calculated on the principle of superposition； secondly， according
to the water flow resistance between oil and injection wells and bottom hole flowing pressure of oil and injection
wells， theplanedistributioncoefficientofdifferentoilwelldirectionsiscalculated， thenthewaterdiversionquantity
of injection well layers is calculated； finally， the separated layer water cut of each oil well is calculated based on the
dynamic development data of oil wells， and eventually the effect of oil well is obtained. Besides， the corresponding
program is compiled according to the relevant theory of the prediction model， and the model is applied to predict
the profile control effect of a real well group.

Micro-Force Calculation in Residual Oil Displacement by Viscoelastic Fluid

WANG Chun-sheng;YANG Shu-ren;LIU Li-li

2011, 33(4):  135-138.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.025

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To further explore the displacement mechanism of flexibility of the polymer to the residual oil， upper-
convected Maxwell constitutive equation is selected， and flow equations of the viscoelastic fluidflow in porous
road are established. The horizontal deviatoric stress difference on the residual film iscalculated on the basis of the
stress tensor theory. The impacts of the different rheological fluid， thewidth of oil film， and pressure gradient on
the horizontal deviatoric stress difference on the residualfilm are analyzed and compared. The results show that：
When flooding with water， power law fluid（n = 0.6） and viscoelastic fluid（We= 0.3） ， the ratio of horizontalde-
viatoric stress difference on the residual filmis about 1：10：25 at actual oil production mean pressure gradient of
0.02 MPa/m， which means that the driving force of viscoelastic fluid（We = 0.3）on the film is about 25 times
the water flooding. This innovative conclusion that the microscopic displacement efficiency can be improved by
viscoelastic fluids is further proved theoretically.

Laboratory Simulation Experimental System for Monitoring Sand Production inHeave Oil Wells

LIU Gang;JIA Zong-wen;JIN Ye-quan;MU Zhe-lin;YU Jiao-jiao

2011, 33(4):  139-143.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.026

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In this paper， based on the system for monitoring sand produced in offshore heave oil wells， a sensor
highly sensitive to the vibration intensity of the grain impacting the sheet metal is designed， and also the way to
collect these signals during the sand monitoring experiment. Using a piezoelectric acceleration sensor to tell the
high-frequency vibration signal caused by the sand impact， and analyzing the sand signal in frequency domain and
time domain by applying the signal processing. The experiment for different sand contents in the heave oil（the
viscosity is higher than 100 mPa·s）is successful under the laboratory condition. The results show， if the grain size
of sample and sand transport flow velocity are the same， and with the increase of sand content， the power spectrum
amplitude， the root-mean-square value and the variance of sand monitoring signal increase as well.

油气化学工程与化工

Research on Binary Foam Flooding Property Influence Factors

LIU Hong-sheng

2011, 33(4):  144-148.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.027

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The foam effect on improving the core sweep efficiency and reducing permeability are investigated
by foam flooding in porous media experiments. The influence of α-olefin sulfonate （AOS ） ， hydrolyzed polyacry-
lamide （HPAM）concentration， gasliquidratio， corepermeability， andinjectionmethodsonfoamfloodingproperty
are explored. The experiment results show that foam flooding resistance coefficient and residual resistance coeffi-
cient increase with the increasing concentration of AOS and HPAM. The foam flooding resistance coefficient and
residual resistance coefficient in the non-oil rock heart are more than three times of those in the oil-bearing rock.
Under the condition that AOS and HPAM concentration are greater than a certain value， foam flooding resistance
coefficient and residual resistance coefficient are stabilized. Appropriate increasing ratio of gas-liquid can improve
foamfloodingcontrolability， buttoomuchratioofgas-liquidwillcausegaschanneling. Thesamefoamsystemdoes
not improve flooding control ability of all different permeability cores. Advanced foam injection leads to the best
mobility control than other ways. The mobility control of the alternating injection of liquid and gas foam decrease
with the increase of alternating slug.

Effect of Low Temperature Air Oxidation on the Composition of Heavy Oil

TANG Xiao-dong;;SU Xu;CUI Ying-xian;;YANG Kai;ZHENG Cun-chuan

2011, 33(4):  149-152.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.028

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In the low-temperature oxidation simulation experiments of Liaohe heavy oil， the change of composition
and nature of gas and heavy oil before and after the oxidation reaction of different system is inspected. The results
demonstrate as follows： The low temperature oxidation reactions occurred between heavy oil and air is oxygen-
addition reactions， which decreases the oxygen content in the gas to 2.71%， consumes 87% of the oxygen in the air，
and increases the acid number and viscosity of heavy oil. Water promoted oxidation of heavy oil makes the resin
content decrease 13.95%， the asphaltene content increase 4.81%， the total resin and asphaltene content decrease，
and the heavy components degrade 17.94%. The naphthenate catalyst system has an excellent catalytic oxidation
activity， which promotes the oxidation and cracking of heavy oil. Water promotes heavy constituent crack in the
low temperature catalytic oxidation reactions occurred between heavy oil and air.

Anti-High Temperature Drilling Fluid System with Calcium Humate

YANG Li

2011, 33(4):  153-156.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.029

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Drilling operations have set an increasingly higher requirements on heat resisting capacity of drilling
fluids， and the conventional drilling fluid systems could not well met the requirements of the deep or ultra-deep
well drilling. based on calcium humate heat resisting mechanism， the experiments and ways of evaluation including
drilling fluids in high temperature rolling， rheological characteristics， and fluid loss property are carried out， and
the performance of drilling fluid system which could be influenced by different CaO and increasing bentonite is
comparatively analyzed. Anti-high heat fluid loss additives such as CMC， SMP， FV-2 are optimally screened， and
a series of calcium humate drilling fluid system with anti-high heat（180℃）and anti-salt（30% ）is raised. The
results show that the optimal base fluid contains 0.3%CaO， 7%SMC and 5% bentonite， while the optimal calcium
humate drilling fluid system contains 7% SMC， 0.5% CaO， 5% bentonite， 5% SMP-1 and 0.3% FV-2， which has
an excellent resistance to high heat of 180℃ and high salinity of 30%.

石油机械工程及其他

Integrity Assessment of Pipeline with Dents

JIAO Zhong-liang;SHUAI Jian

2011, 33(4):  157-164.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.030

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The depth-based evaluation criteria have not been able to meet the engineering requirement concerning
the pipeline stress concentration caused by dent， so this paper proposes strain-based evaluation procedure composed
of inline detection， noise treatment， geometric interpolation， and strain calculation. Plain dent has little influence on
pipelineresidualstrength， butitmayacceleratepipelinefracturefailurewhencombinedwithweld， crack， scratches，
and other defaults. The elastic-plastic fracture theory can be used for the strength evaluation， but when the dent is
near a weld， it must be repaired or replaced. Unconstrained dent faces the fatigue problem when internal pressure
fluctuate. The fatigue life and maintenance period are predicted based on rainflow method and fatigue damage
cumulative rule. According to the analysis and comparison of main standards and rules， this paper proposes a
completely integrity assessment system of pipeline dents.

The De-Noising Method of the Drill Testing Signal Based on Wavelet Transform

SHI Ge-meng;LI Bin

2011, 33(4):  165-168.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.031

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There are cyclical dynamic shocks between the bit body and rocks during the rocks breaking tests. Mean-
while， due to the influence of the test equipments and environmental factors， a lot of noises appear in the drill test
signals， which make it impossible to get accurate test data. Thus， the results often can not truly reflect the charac-
teristics and laws of tests. In this paper， a set of noise removing methods are established on the basis of the floating
threshold algorithm of wavelet transform. After the process and analysis on the practical test data， the methods are
demonstrated to have a good filtering effect on the noise， and are able to improve the accuracy and reliability of the
signal.

177.8 mm Liner Cementing Technology in Well AT21X

LU Chang-qing

2011, 33(4):  169-172.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.032

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Well AT21X， which is an ultra-deep exploration well in Tahe Oilfield， adopts the ϕ 177.8 mm liner
cementing. The cementing operation is difficult owning to the deep depth， high temperature in the bottom hole，
high content of chloride ions and special well-structure. During the cementing， two slurries of different setting
times were used. In the slurries， 2% micro-silicon and 0.2% TAS153 were used to solve the problems caused by
the high temperature， high salt content， easy channeling and high water-loss when cementing an interval containing
salt formation. So the performances of cement slurries were improved as well as the cementing quality. Cementing
quality test result is that 100% cemented intervals are qualified， 90% good and excellent. The cementing technique
used provides a good example and some useful experiences， and can bring some guidance for the future cementing
operations concerning salt formation.

博导论评

The Technology of Comprehensive Evaluation after the Fracturing Based onUnascertained Mathematics Theory

GUO Da-li;ZHU Kai;CHEN Chao-feng;ZHANG Tian-xiang;JI Yong

2011, 33(4):  173-176.  DOI: 10.3863/j.issn.1674 – 5086.2011.04.033

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With the development and application of hydraulic fracture technology， a method which could evaluate
the underground hydraulic fracture economically and properly is urgently needed on the spot. As the results of the
current various technical assessment are uncertainties， inconsistencies and the immaturity of the technology itself，
this paper has researched on the comprehensive evaluation problem of hydraulic fracturing， put out the model to
comprehensively evaluate the associated fracturing parameters， such as the fracture length， the fracture height，
the fracture width， the fracture conductivity， the fracture closure pressure， the comprehensive fracturing fluid loss
coefficient， etc. and offered the solutions of the model which takes the various certainty information， uncertainty
information， fuzzyinformationandgreyinformationallintoconsideration. Atlast， theapplicationisalsodiscussed，
and its effectiveness and practicality have been showed by examples.