Table of Content

01 June 2014, Volume 36 Issue 3

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Domestic Status and Thoughts on the Development Ideas of Deepwater
Drilling Heave Compensation System

Liu Qingyou, Xu Tao

2014, 36(3):  1-8.  DOI: 10.11885/j.issn.1674-5086.2013.12.07.01

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Heave compensation system is the key equipment of the floating drilling platforms and the drill string which has the
appropriate compensation for doing heave motion at times of waves and other natural loading，in the process of developing deepsea
oil drilling. The device can effectively reduce a series of impact that oscillating up and down movement has on drilling，
ensuring the stability and safety of the overall process of drilling system and the stability of the downhole drilling pressure.
Through the extensive literature survey，analysis of the situation of the development and application of heave compensation
system in our country was made. Combined with application and research status of the heave compensation device in our
country，and by using the theory of multiple floating body and drilling dynamics characteristics，we put forward new ideas
on further in-depth study and the technology roadmap of the device，to promote China′s offshore oil equipment independent
research and development.

Characteristics of the Carboniferous Volcanic Fractures and Its
Hydrocarbon Accumulation Significance in Hala′alate Mountains

Zhang Guanlong, Zhang Kuihua, Wang Shengzhu, Xu Wenguo

2014, 36(3):  9-18.  DOI: 10.11885/j.issn.1674-5086.2014.01.28.02

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Hala′alate Mountains Area，situated in the foreland fold thrust belts of the northwestern margin of Junggar Basin，
adjacent to hydrocarbon generation depression of Mahu，is a favorable area of hydrocarbon migration and accumulation. Carboniferous
hydrocarbon reservoir in this area was mainly hosted in the volcanic tectonic fractures and its enrichment regulation
was unknown. Aiming at this problem，we study the development characteristics，controlling factors of tectonic fractures and
its relationship with hydrocarbon accumulation. By using drilling core，imaging logging，rock mechanics tests and fluid inclusion
analysis technics，the paper studied the attitude，density，developing order，main controlling factors of Carboniferous
volcanic tectonic fractures and their relationship with hydrocarbon accumulation. The results show that the cracks in carboniferous
volcanic rocks are mainly high angle cracks，and the advantage fracture development tendency is northeast-southwest；
the main controlling factors are rock mechanics properties and structural position. Besides，due to the low filling rate，late
forming time and well matching with the major hydrocarbon migration and accumulation，the high angle fractures became the
main hydrocarbon exploration area. The results have very important guiding significance for the exploration and development
of Carboniferous volcanic hydrocarbon reservoir in Hala′alate Mountains Area.

Fault Characteristics and Hydrocarbon Geological Significances in
Rongxingtun Structural Zone of East Sag，Liaohe Depression

Chen Guomin1, Li Sanguo2, Wang Haifeng3, Shi Linchun4, Gao Jianjun4

2014, 36(3):  19-26.  DOI: 10.11885/j.issn.1674-5086.2013.08.06.01

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There are lots of hydrocarbons discovered in Rongxingtun Area，Eastern sag，Liaohe Depression，while the obscure
and complex distribution of fault system caused difficulties for revealing hydrocarbon distribution and limited the further exploration
in this area. To reveal the fault characteristics and its geological significance，we delineated the classes，characteristics
and spatial combination characteristics of the faults by using the seismic profile，structure map and balanced section. The study
reveals that the faults properties，characteristics and evolution are very complex，which can be divided into the main faults
with north-east distribution and the secondary faults with north-west direction in the plane. They are superposed by three kinds
of fault systems in vertical direction，the extension faults in the third section of Shahejie Formation，the Dongying strike-slip
faults and Guantao compression faults separately. Three different fault systems superposed on the vertical direction. This kind
of complex fault systems deeply affect the formation，distribution and adjustment reservoir；specifically，the difference activities
led to the convex concave and basic tectonic framework and the formation of reservoirs，and controlled the hydrocarbon
source，various types of traps and volcanic-sandstone-mudstone reservoirs architecture：such characteristics make the fault system
the main channels for hydrocarbon migration and important clues to find oil，and most of the reservoirs are attached to the
faults and its related structure at different hierarchy.

Carbon and Oxygen Isotope Stratigraphy Research in Chashgui Area

Wang Qiang1，2, Wang Xingzhi1, Xu Jianliang2, Liu Bin3, Zhang Qin2

2014, 36(3):  27-34.  DOI: 10.11885/j.issn.1674-5086.2014.02.24.04

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The effective reservoir in Chashgui Area，Turkmenistan，is Callovian–Oxfordian carbonate rocks. Since the GR
curve does not varies much，it is difficult to predict the favorable reservoir distribution. Using the carbon and oxygen isotope
from the 41 samples out of the core of the Well Cha-21 in Chashgui Area，combining with the data of the sedimentary evolution，
this paper discusses the sea-level changes during the sedimentation of the Callovian–Oxfordian reservoirs. It is shown that the
information in the oxygen isotope has been damaged，and the information in the carbon isotope has been preserved. So the
carbon isotope can be used to study the isotope stratigraphy and analyze the Palaeo-environment. The calculated salinity index
is 128.25～136.63，which is higher than the division standard between brine and freshwater，so the diagenetic fluid is high
salinity brine. The carbon-isotope stratigraphic curve is almost consistent with the global sea-level curve，which proved that
the reservoir geologic period is really Callovian–Oxfordian. According to the sea-level change curve，the main reservoirs
in Callovian–Oxfordian are divided into 3 sedimentary cycles and 5 evolutionary phases. Those results fill up the blank in
the isotopic stratigraphy studies，which are important significance for the in-deep understanding of the law of sedimentary
evolution，and predicting the favorable blocks.

Main Controlling Factors of Effective Reservoir in the Second
Section of Bayingebi of Chagan Sag

Zhang Fangdong1, Wang Xuejun1, Rao Lei1, Zhou Yan1, Liu Qingwei2

2014, 36(3):  35-44.  DOI: 10.11885/j.issn.1674-5086.2013.12.17.03

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Chagan Sag is a Mesozoic sedimentary sag，the second section of Bayingebi is the main hydrocarbon generation
interval. Fan delta surrounds the sag，and the fan delta sedimentary is of coarse granularity，fast phase change and poor physical
property. The main controlling factors of hydrocarbon accumulation are effective reservoir. Based on the studies of precipitation
facies，diagenesis，reservoir prediction about the mechanism of effective reservoir generation and distribution，we understand
that physical properties of different facies of fan delta are largely different，and plain subfacies is of high content of glutenin of
matrix，poor sorting and reservoir density；outside frontal subfacies is of thin rock granularity，weak hydrodynamic，high shale
content and poor reservoir physical property；in front distributary channel microfacies is fine microconglomerate and gritstone
of fine sorting and low shale content. Calcium cementation compaction plays an inhibitory effect in the early diagenesis，which
creates the conditions for later dissolution，and Alkaline sedimentary environment and diagenetic evolution of sedimentary are
helpful to form dissolution pores. In Chagan Sag，hydrocarbon accumulation has the characteristics of oil and gas storing in
frontal fan delta–plain block–close range migration in the store–the tectonic setting control. Based on the above understanding，
we focus on the anatomy of the Wuliji structure zone，and make a breakthrough of the thin oil exploration in the fan delta front.

Reservoir Characteristics and Controlling Factors of M55 Sub-member of
Majiagou Formation in the East of Sulige Area

Zhu Guangshe1，2, Zhao Junxing1，3, Shao Xiaoyan2, Li Fengjie1, Ji Mingming1

2014, 36(3):  45-53.  DOI: 10.11885/j.issn.1674-5086.2013.12.19.02

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Abstract：As the new member of oil-gas exploration，breakthrough in oil-gas exploration has been made in resent years at M55
Sub-member of Majiagou Formation in Ordovician. On the basis of the survey of core of well drilling，analysis of well logging，
identification of lamela，analysis of physical characteristics，the article studied the reservoir characteristics and analyzed the
controlling factors of reservoir in M55
Sub-member of Majiagou Formation in the east of Sulige Area. It suggested that the
main reservoir is a dolomite gas pool in M55
Sub-member in the east of Sulige Area and there is fine corresponding relationship
between the gas pool and dolomite. The intercrystalline pore is the main type of reservoir space. Among all kinds of rocks，the
medium crystalline dolomite，fine crystalline dolomite and powder crystalline dolomite have the best physical characteristics
of reservoir. The sedimentary microfacies mainly provided the material basis for the development of reservoir and the dolomite
controlled the distribution of effective reservoir. Besides，the diagenesis of buried period in the middle and later period is the
most beneficial to the reservoir development. Meanwhile，nose structure has certain influence on the gas pool，while paleokarst
takes little effect on reservoir in M55Sub-member.

Stability and Formation Mechanism Analysis of Secondary Migration
Pathway of Hydrocarbon

Jiang Lin1，2, Bao Dongmei1, Hong Feng1，2, Hao Jiaqing1，2, Fan Yang1，2，3

2014, 36(3):  54-58.  DOI: 10.11885/j.issn.1674-5086.2013.08.11.05

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Abstract：In order to accumulate in effective trap，hydrocarbon generated form source rocks has to go through a certain
distance of secondary migration，therefore the process of hydrocarbon secondary migration has a great influence on ultimate
hydrocarbon accumulation rate. The secondary migration process of crude oil can be divided into two types：piston pattern and
advantage pattern；the secondary migration of gas is an intermittent migration process composed of piston pattern and advantage
pattern. The difference of secondary migration pattern leads to the differences in the migration pathway stability between oil
and gas. This study used dyed kerosene and nitrogen to conduct physical simulation experiment of secondary migration process
respectively，and discussed secondary migration pathway stability of oil and gas through way of more than one filling，and
analyzed its formation mechanism in view of the different physical characteristics between oil，gas and water and the relation of
the difference to porosity of reservoir rock. In our opinion，a fairly stable migration pathway could be formed in the process of
oil secondary migration，so its transport efficiency is higher；natural gas forms a relatively stable dynamic migration pathway
in the process of secondary migration，the loss amount while migrating is larger.

Resistivity Section Characteristics and Exploration of the Oil
Shale Layer in Tongchuan Area

Wang Kai, Zhang Xu, Tang Shengsong, Jiang Ting

2014, 36(3):  59-67.  DOI: 10.11885/j.issn.1674-5086.2012.10.11.04

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Abstract：In order to study the suitability and resolution of resistivity sounding method in oil shale region，we carried out
the resistivity sounding in Tongchuan Area，the south of Ordos Basin. Combined with drilling mud logging and discovery ore
situation，analysis of the oil shale section resistivity features by two methods is made，and the specific areas of oil shale layer
in the electrical section are selected. Oil shale layer thickness is thin and high resistance layer in target body，compared to bury
depth. In the obtained electrical section，the resolution of high resistance electrical oil shale layer is not very clear，but resistivity
isoline change of gradient zone corresponds well to oil shale layer position，indicating the oil shale layer position indirectly.
And through the comprehensive analysis of lithology and logging parameters，we think the gradient changes of resistivity values
with depth changes resistivity value with depth describes from electrical aspect the evolution of oil shale layer from shallow
lake sedimentary environment to half deep lacustrine environment. Therefore we conclude that resistivity sounding method can
achieve the purpose of the exploration of oil shale layer.

Analyzing the Effect of Rock Electrical Parameters on the Calculation of
the Reservoir Saturation

Li Xiongyan, Qin Ruibao, Liu Chuncheng

2014, 36(3):  68-74.  DOI: 10.11885/j.issn.1674-5086.2012.10.11.01

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Abstract：Based on the Archie formula，the effect of variable m and n on the saturation is analyzed，and the error formula of
calculating the water saturation of reservoirs caused by the error of m and n is derived. On the basis of the loose sandstone，
medium sandstone，tight sandstone，conglomerate，tuff，breccia，basalt，andesite，dacite and rhyolite，this paper first analyzes
the distribution range and change amplitude of m and n. Secondly，the impact of m and n on the calculation of the water
saturation of reservoirs is discussed. With regard to each lithology，the distribution range and change amplitude of m is greater
than those of n. Therefore，compared with n，the effect of m on the saturation is stronger. When the error of m is ±0.2，the
error in the calculation of the water saturation of reservoirs is almost all above 5%，and the maximum is even more than 30%.
Meanwhile，when the error of n is ±0.2，the error in the calculation of the water saturation of reservoirs is almost all below 5%.
The influence of m and n on the saturation is determined，and the error in the calculation of the water saturation of reservoirs
caused by the error of m and n are calculated. It is theoretically and practically significant to the precise calculation of saturation
of complex reservoirs.

Application of Support Vector Machine to the Prediction of the Thickness
of Channel Sand Based on Seismic Attributes

Shen Jiagang1, Song Zongping2, Guan Xiaowei1

2014, 36(3):  75-81.  DOI: 10.11885/j.issn.1674-5086.2012.10.29.01

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Abstract：Main reservoir of Fuyu layer of middle and shallow part of northern Songliao Basin is channel sandy body，which is
characterized by its thin thickness，small sedimentary scale and lateral heterogeneity. With regard to this problem，we present the
model of support vector machine as a solution. By the optimization of the combination of effective seismic attributes，including
amplitude，frequency，phase，seismic waveform classification and coherent，the best group was for the final input data. Then
the key parameters of the SVM model include loss function C，insensitive loss function parameters ε and γ coefficient，and all
of the well point data was involved in the calculation to indicate the thickness of the channel sand. The result can maintain the
lateral resolution of the seismic data and reflect its general sedimentary pattern as well. The result of subsequently drilled wells
indicated that this method has good qualitatively predictive ability for the thickness of channel sand.

Combined Broad-seis Survey Design of Streamer and OBC

Li Yanqing

2014, 36(3):  82-86.  DOI: 10.11885/j.issn.1674-5086.2012.09.29.01

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Towed streamer seismic acquisition is used in the traditional marine seismic exploration，and the signal-to-noise
ratio of the collected data are greatly influenced by external environment. The influence of environment on seismic data can be
reduced by changing the depth of the streamer. It´s difficult to collect broad-seis data in China sea due to the limitations of seismic
equipment. In order to break the limitation，a combined broad-seis survey of streamer and ocean bottom cable（OBC）was
discussed in the article. There are four key techniques in survey design，including parameter argumentation，bin combined，
feather angle and depth optimization. In parameter argumentation the method to compute line spaces through the most shallow
purpose layer is discussed. For the space differences between towing and submarine cable detector，bin combined method
was designed. In the situation of feather angle existence，we discussed the effect of horizontal change rate on limited wave
point frequency and energy in data collection. In the end，we discussed the optimization of sinking depth of towing through
depth changing test. Through analysis of these techniques，we have established the basic process of survey design of combined
broad-seis acquisition of streamer and OBC.

Dynamic Prediction Model of Edge-water Gas Reservoir Based on
Water Invasion Early Warning

Li Zhijun1, Qi Zhilin1, Su Yaxian2, Li Jiqiang1, Yan Wende1

2014, 36(3):  87-92.  DOI: 10.11885/j.issn.1674-5086.2014.02.13.05

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Abstract：Water invasion can maintain the reservoir pressure and keep the production of gas wells for water-drive gas reservoir.
The gas well production performance will be affected by the sharp decreasing of gas permeability when the water breaks into
the well-bottom. It is very important significance for development technical adjustment to accurately predict the distance of
edge water advancing and to early warn for the water invasion. Based on the principle of volume balance of water invasion
circle of edge water gas reservoir，the formula of water invasion proximity warning was firstly proposed，then the prediction
models of production rate，pressure and water invasion volume were considered in this article，and a new prediction model of
edge-water gas reservoir production performance considering water invasion proximity warning was proposed，and a real case
study on Puguang Gas Reservoir was conducted finally.

A Study on Fracture Vuggy Reservoir Multi-scale Flow Simulation
Based on Pseudo-particle Method

Zhang Hongfang, L¨u Xinrui, Liu Zhongchun, Han Kelong

2014, 36(3):  93-100.  DOI: 10.11885/j.issn.1674-5086.2012.11.19.08

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Abstract：Fractured vuggy reservoirs have various types of reservoir space which are greatly different. There are many typical
multi-scale and multi-phase complex flow states in the reservoir，including flow in porous medium，free flow in the cave，etc.，
which makes it difficult to accurately describe the flow characteristics of such reservoirs based on the physical simulation results
and conventional numerical simulation methods. In this paper，we establish two phase flow multi-scale discrete calculation
models based on pseudo-particle method. Relying on its advantages in the interface tracking，simulated the surface tension
through introducing a repulsion between the two phase interfaces，the surface tension model is established to realize the two
phase flow simulation of fractured vuggy reservoirs. Then we verified correctness of the model through theoretical analysis
and comparison with the physical experimental phenomena. The results show that this method can simulate two phase flow of
this type reservoir in different scale，which can replace the physics simulation experiment，and determine the distribution of
remaining oil in different fractured vuggy combination type as well as can simulate large scale macroscopic reservoir，it is to
lay a foundation for efficient development of this type reservoir.

Transient Fluid Flow Coupling Model and its Solution About
Two-stepped Horizontal Well

Li Miao, Ji Bingyu

2014, 36(3):  101-106.  DOI: 10.11885/j.issn.1674-5086.2012.01.09.01

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Abstract：The study of percolation theory and deliverability analysis for two-stepped horizontal well is imperfect at home and
abroad. Based on the horizontal well unstable flow model and the potential superposition principle，the two-stepped horizontal
well unstable flow model is established by using a semi-analytical method and by considering the variable mass flow within the
wellbore pressure loss，the solution of the coupling model is presented under the bottomhole constant pressure. The research
results of the real examples show that the productivity index distribution along the borehole is non-uniform，which is the
asymmetric“U”shaped pattern. The productivity index at the heel is slightly higher than that at the toe. There is an obvious step
on the curve of pressure difference distribution along the wellbore，which shows that the pressure loss at the connection section
is larger. The results are meaningful and provide a theoretical basis for the two-stepped horizontal well casing design，and for
designing the field development project，computing development indicators，formulating development adjustment programs，
and therefore，to efficiently develop the complex oil and gas fields.

Flow Units Classification Based on Reservoir Architecture and Its
Influence on Reservoir Development

Xiong Guangqin1, Liu Li2

2014, 36(3):  107-114.  DOI: 10.11885/j.issn.1674-5086.2014.03.02.01

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Reservoir heterogeneity is severe and fluid flow is very complex in delta reservoir，which limits the reservoir
development. Taking E1 f 43 reservoir of Nanhu Oilfield as an example，flowing barrier recognition method based on reservoir
architecture and flow unit classification method based on multiparameter cluster analysis and stepwise discriminate analysis
are used. Flow barrier distribution and flow unit development rule are studied with the above methods and development data.
Connection of different flow unit composite models is analyzed and the influence of flow barrier and flow difference on oil
development is summarized. The study revealed that：（1）developed two kinds of reservoir sandbodies，sheet sand and stripped
sand. In stripped sand，water injection is usually invalid because the injection well and oil well are separately in sand and flow
barrier. This forms remaining oil.（2）Developed 5 types of flow units and types II and III are the main types.（3）There are 5
different flow unit composition model in connected sand bodies which have different connectivity，which form flow difference
surfaces inside connected sand bodies and weaken the permeability. These surfaces limit the reservoir development and enrich
remaining oil.

Fast Pressure Decline Analysis of Fracture Calibration Tests

Wang Fei, Zhang Shicheng, Cai Jiujie

2014, 36(3):  115-120.  DOI: 10.11885/j.issn.1674-5086.2014.02.14.01

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Abstract：Due to the lack of simple and effective pressure decline analysis methods of fracture calibration tests，the pressure
decline behavior of a fracture calibration test was investigated. The numerical simulation results show that four flow regimes
of the fracturing fluid in formation and fractures，i.e. fracture extension，fracture elastic closure，after-closure linear and radial
flow，can be identified. Its differential pressure derivative plot successively shows 1/2 slope，3/2 slope，1/2 slope and 0 slope
lines on the log-log coordinate. Further，a fast method which can firstly diagnose the downhole pressure monitoring data in
log-log plot was proposed. Then the key parameters of the fracture reservoir will be gotten with the analysis of G function，
FL function and FR function，respectively，such as the initial reservoir pressure，closure pressure，formation factor，leakoff
coefficient of fracturing fluid etc. The proposed method was applied to a field case in East Sea，China. The results proved that
the method is reliable and practical in field application.

Technology Research About Super Large Composite Acid Fracturing
Filtration in Tahe Oilfield

Zhang Ye1，2, Yang Shenglai1, Jiao Kebo2

2014, 36(3):  121-126.  DOI: 10.11885/j.issn.1674-5086.2012.10.18.02

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Abstract：In order to meet the needs of super large composite acid fracturing stimulation technology of the carbonate reservoirs
in Tahe Oilfield ，the particle size of 0.150 mm ceramic powder，oil soluble temporary plugging agent and biodegradable fiber
were evaluated in laboratory as filtrate reducer. Ceramic powder can decrease the filtrate loss by nearly 2 L in 15 min compared
with no ceramic powder，the filtration rate drop from 3.3×10-6 m/min down to 2.0×10-6 m/min；oil soluble temporary plugging
agent more than 85%；biodegradable fiber filtration reducing agent，reduce the liquid filtrate volume by 37.70%～22.99% when
temperature is at 80～120 ℃. Given reservoir characteristics and technological requirements of ceramic powder of different
particle size and of the permeability test results，we found that a 0.150 mm particle size powder pottery is applicable to Tahe
Oilfield super large composite acid. Based on the analysis of different action mode of ceramic powder on natural fracture，
ceramic powder was added around 10%，in ascending sequential order. Based on proppant slugs technique principle and fracture
shape，the ceramic powder amount is optimized. In Well TH12227H field test，satisfactory results were obtained，which have
an important guiding significance.

Adaptability Evaluation of CO2 Gas Injection Development for“Three
Low”Offshore Oil Reservoir

Luo Chengdong

2014, 36(3):  127-132.  DOI: 10.11885/j.issn.1674-5086.2012.01.14.01

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In view of the“three low”characteristics（i.e.，low resistivity，low oil saturation and low permeability）of Oilfield
in western South China Sea，water injection and energy supplement difficulties exist in the development process due to high
irreducible water saturation and high shale content and strong water sensitivity. Based on laboratory researches and adaptability
evaluations of gas injection of CO2 at home and abroad，and by taking reservoir as an example，laboratory experiment of CO2
gas injection and reservoir numerical simulation are finished，and theCO2 gas injection development adaptability evaluation is
done on this foundation. A comparison among the depletion type development，continuous gas injection and WAG displacement
through numerical simulation，the result shows CO2 gas injection development has good adaptability，and WAG can further
improve the oil recovery of oilfield development.

Study on Improved Solid Model in Calculation of Asphaltene Precipitation

Xiang Min1, Gong Jing1, Yang Yi2

2014, 36(3):  133-138.  DOI: 10.11885/j.issn.1674-5086.2014.03.25.05

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When the temperature，pressure and the components of the crude oil system change，the asphaltenes will be continuously
precipitated as a solid phase from the liquid phase，then flocculated and deposited onto the wall. Sometimes，severe
deposition problems can block up the operation of wellbore and transportation pipelines. The crude petroleum of the gas-liquidsolid
three phase equilibrium must be studied in order to accurately describe the equilibrium and precipitation process in oil
and gas system which including asphaltene and other organic polymer solid compositions. The characterization of oil and gas
system containing asphaltenes and the calculation of three phase equilibrium are studied，a method which changes three phase
equilibrium calculation into two phase equilibrium calculation is proposed on the assumption that the asphaltene precipitation
does not affect the gas–liquid balance. Though these assumptions，liquid–solid(asphaltene) phase equilibrium is calculated on
the basis of the results of gas–liquid phase equilibrium calculation. Based on the analysis，this article assumes asphaltene is a
solid phase，and develops a gas–liquid–solid phase equilibrium thermodynamic model to simulate the asphaltene precipitation
in gas–liquid–solid phase equilibrium system. This model can consider the effect of standard temperature and standard pressure
on the solid asphaltene fugacity calculation. The results of actual application show that this model is effective to be used to
simulate and calculate the phase envelope and amount of solid asphaltenes in a crude system contained oil and gas.

Experimental Study and Model Evaluation on Continuous Liquid Removal
in Horizontal Gas Well

Wang Qi1, Li Yingchuan1，2, Wang Zhibin1, Cheng Jinjin2

2014, 36(3):  139-145.  DOI: 10.11885/j.issn.1674-5086.2014.01.22.01

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Abstract：The continuous fluid removal of the horizontal gas well is more difficult than that of the vertical wells. To study
the problem of the continuous fluid removal of the horizontal gas well，we have simulated the gas-liquid two phase flow of
the horizontal gas well with the visual gas-liquid conduit flow experimental device. This device is made up of vertical tubes，
which is six meter high，horizontal tubes at ten meters，inclined tubes at six meters long. Through experiments，we found that，
among the vertical，horizontal and inclined tubes，the capability of liquid-carrying of inclined tubes is the worst. So，the critical
liquid-carrying velocity of the inclined tubes can be used as the velocity of horizontal gas well. Droplet and film model of the
inclined tubes are now widely accepted. We observed the phenomena of liquid-carrying and test the critical liquid-carrying
velocity in different inclined angles，which are from 28° to 72° The experiments show that liquid in the inclined tubes is carried
by film form，not droplet form. From the mechanism analysis，the film model is more reasonable. Contrast the test values with
the calculated values of film and droplet model，we can also find that film model is more reasonable.

Laboratory Study on Oil-resistant and High Salinity-resistant Foam
Drainage Agent

Liu Yuee1, Yang Wenwen1, Wu Guodong2, Abudouwaili·A2, Xu Xianghong1

2014, 36(3):  146-150.  DOI: 10.11885/j.issn.1674-5086.2013.03.15.01

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Abstract： In view of the actual cases of a great quantity of liquid loading at bottomhole in the high temperature and gas
condensate wells at the later stage of development，a foam agent which has good foaming ability and stability under the condition
of the high temperature and condensate oil is developed，which could largely improve the gas recovery factor and keep the wells
stable and of high recovery rate. In this paper，we have evaluated the foaming ability and stability of many kinds of foam agents
under the condition of different concentration and condensate oil content by improving Ross-miles method. Finally，we have
selected SDS，CAB，SBFA–30 to make compositional formulation and added a certain amount of polymer（PVA）to increase the
stability of the foam. We have got the optimized formulation（0.1%SDS+0.1%CAB+0.05%SBFA–30+0.02PVA）by orthogonal
experiment design and evaluated the foaming force under the condition of high temperature and condensate oil. The results
showed that it could keep good foaming and foam stabilization performance under the condition of the 150 ℃ and 50% high
condensate oil.

Study on the Property of Controlling Filtration by Viscoelasticity of a
New Associated Fracturing Fluid

Lin Bo1, Liu Tongyi1，2, Tan Haobo3, Wei Jun1

2014, 36(3):  151-156.  DOI: 10.11885/j.issn.1674-5086.2012.04.05.02

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A new associated fracturing fluid（GRF）with non-building capacity was studied in this paper. Because it has
no wall building capacity，a simple device for filtration measurement suitable for this kind of fracturing fluid was designed，
and the methods for filtration measurement were also developed. The evaluation results show that the filtration property of
GRF is better than before. The influence of the viscoelasticity on filtrational resistance in the porous medium was studied with
RS6000 flowage meter and the core displacement device. The results show that GRF fracturing fluid can establish effective
filtrational impedance（R0）in core pore owing to its excellent viscoelasticity；the stronger the viscoelasticity is and the lower
the core permeability is，the larger R0 is，and the more difficult the fracturing fluid filtrates；the test results further indicate that
the viscoelasticity of the liquid is the most important factor to filtration controlling，and the influence of apparent viscosity and
viscoelasticity on the fluid loss was studied in the paper. Therefore we conclude that viscoelasticity of GRF fracturing fluid can
control its filtration.

Elastic-plastic Fracture Mechanics Analyses of Surface Cracks in
Drill String Subjected to Combined Loading

Zhao Guanghui, Wang Haohan, Shi Jian, Zhao Li

2014, 36(3):  157-164.  DOI: 10.11885/j.issn.1674-5086.2013.12.09.01

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Abstract：The drill pipe near the surface stands the largest tension and torsion in the whole drillstring especially during drill
pipe sticking or bit bouncing. As an example，a 5 inch drill pipe made of 30CrMo that was near the well head of an ultradeep
straight well was analyzed here. Simplifying the crack of the drill pipe as circumferential semi-elliptical surface crack
and using the fitted Ramberg-Osgood equation as constitutional relation，we simulated elastic-plastic fracture feature of the
drill string under combined loading of axial force and torsion corresponding to its drilling behavior. The transition aspect
ratios are determined for the given combined loading and the crack shape could be determined approximately corresponding to
different crack depths. The contribution of the plastic J-integral is estimated and the effect of material nonlinearity on the crack
propagation is described. Variations of J-integral as a function of axial force and torsional moment respectively are compared，
and the dangers from tension and torque fluctuation are evaluated quantitatively. Compared with tension，fluctuation in torque
contributes much more to crack propagation. It is an important significance for increasing drill string′s service life to avoid the
drill string from severe torsion impact.

Numerical Simulation of Annulus Flow Field for Under-size
Stabilizer Annulus

Chen Yingjie1, Deng Chuanguang1, Chang Hongqu1, Li Xiangbi1, Ma Tianshou2

2014, 36(3):  165-172.  DOI: 10.11885/j.issn.1674-5086.2013.06.08.03

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Abstract：The under-size stabilizer have multiple functions in the steerable drilling for shale gas，which could not only control
well trajectory，but also help reduce friction/torque，reduce the risk of drilling resistance and improve hole cleaning status. While
the annulus flow characteristics and mechanism of the inadequate spiral stabilizer are not perfect. To solve these problems，we
stimulate the annulus fluid flow characteristics of the inadequate spiral stabilizer with the turbulent viscosity model method and
Realizable k-epsilon turbulence model，and the results show that：the annulus flow around the stabilizer inlet section is more
stable，beginning to appear in flow close to the position of the stabilizer；in the stabilizer annulus downstream section（lateral
stabilizer and outlet section），the annulus velocity，total pressure and distribution of the dynamic pressure bears axis symmetry
flow respectively. The formation，development and distribution of this section are the spiral shape，which is good to clearing
borehole cuttings bed. In addition，the eddy flow amount is big and，the development of streamline is irregular，which means
the spiral structure of the stabilizer leads to the fluid flowing around. The around flow forms a large number of eddy flow，
accompanied by a greater dynamic pressure，and the induced exciting force by dynamic pressure will increase the vibration of
drill string.

Study on the Erosion Law of Gas with Cuttings Against Tool Joint

Ming Xin1, Lian Zhanghua1, Lin Tiejun1, Chen Xinhai1, Zheng Jianxiang1，2

2014, 36(3):  173-178.  DOI: 10.11885/j.issn.1674-5086.2013.11.04.02

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Abstract：Severe erosion against the tool joint always leads to rapid failure of the drill pipe in gas drilling. In order to understand
the mechanism of this problem，we established the CFD model of the erosion of gas with cuttings against the drill pipe with
18° slope based on two phase fluid theory. According to this model，systematical studies have been made about the effects of
different eccentricity，injection volume of gas，and drill rate on the erosion rate against the tool joint，and on the trajectory and
distribution of cuttings and gas velocity. The results show that：at the first，when the drill pipe is in the cylindrical center of
borehole，the distribution of erosion rate is symmetrical，the erosion against tool joint is more severe than against the drill pipes’
body and the maximum erosion rate is near the windward slope top. Meanwhile，the quantitative relationship between cuttings’
mass flow rate，gas velocity and the maximum erosion rate has been worked out. And then，the maximum erosion rate against
the drill pipe and the erosion rate against the tool joint on one side of the wide flowpath are more severe when the drill pipe is
eccentric. The maximum erosion is transferred from the joint to the drill pipes’ body when the drill pipe eccentricity from 30%
to 70%. The maximum erosion rate against the tool joint increased with the increase of gas velocity when drill pipe eccentricity
was at 0～30%，50%～70% and 80%～90%，respectively. But the maximum erosion rate against the tool joint decreased with the
decrease of cutting concentration in wide flowpath when drill pipe eccentricity was at 30%～50% and 70%～80%，respectively.
All the results from these studies provide the theoretical support for preventing failure of the tool joint and were applied in some
oilfields.

Network Simulation of Formation Damage Due to Suspended Particles
in Injection Water

Feng Qihong1, Han Xiaodong1，2, Wang Shoulei3, Zhang Xin1, Zhou Wensheng3

2014, 36(3):  179-184.  DOI: 10.11885/j.issn.1674-5086.2012.08.30.13

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Abstract：Particles suspended in injection water could damage the formation and decrease the permeability. And it’s of great
importance to study the impact of various factors on the formation impairment for its prevention and treatment. In our study
here，pore scale network modeling method is applied to the study of the formation damage patterns and the change of the porethroat
radius under various conditions. In network models，different microcosmic particle variation mechanisms are taken into
consideration. The results indicate that the pore-throat radius will decrease with the process of waterflooding and pore-throats
that are closer to the inlet face will have a much higher decrease of their radius. Besides，the lower the flow rate is，the higher
the particle concentration in injection water is，the lower the fluid viscosity and bigger particle size，it will be beneficial for the
formation damage.