The reservoir heterogeneity which is under the macrocontrol of the paleogeographic setting, stratigraphic framework, sedimentary facies belt, and fault is under the control of rock type, diagenesis and porestrucue etc. First, the planar distribution of micro-facies of the Fourth Member of Shahejie Formation of Fault Block 81 is compiled by means of mapping method of predominant facies under the guidance of winnow-deposition sedimentation. Then the reservoir heterogeneity of the target zone is studied quantitatively and semi-quantitatively by means of thereexplanation result of well logs including porosity, permeability and oil saturation data etc. The conclusion is drawn as follows: the innerbedded heterogeneity is high, the interbedded heterogeneity is relatively high, and the plane heterogeneity is relatively high. Last, the distribution map of fault system and flooding unit is improved. It can serve the project setting of the oil field.
In Weicheng oil-field, the porosity is 14% and the permeability is(11~12)×10-3μm2. Moreover, the formation of Weicheng oil -field has the character of high shale content and high salinity. So the interpret results of conventional logging of oil- field have not reliability. Chlorine loggng whic ia ggig method of pulsed neutron logging can recognize the oil-bearing of low resistance, determinate the porosity and the remaining oil saturation and the watered-out area and the water-out degree and the water-oil contact and so on. It can complete the neutron lifetime log (NLL) and carbon/oxygen ratio log and the combination of induced polarization electrometric method log and the spontaneous potential (SP).So it is a good monitoring method of the development post-period high saliity oil-field. The pracal data verifies the validity of this method.
Two methods to identify gas zone are presented in the paper, one is called DEN-CNL curves enveloping inter-zone, the other is named porosity overlapped, they are all used successfully in the interpretation of 40 wells' logging data in Su-6 area. The paper gives a lot of examples and explicates how to use the methods to identify different hydrocarbon, such as gas zone, water zone, gas-water zone or non-production zone. The advantages of using this method to evaluae reservoir Sulemiaorea is that it can distinguish low-resistivity from water zone efficiently. This technology is proved effective by well test data.
The intrusion of magma in a sedimentary basin can lead to the change of the geothermal history of the basin, and the huge heat energy of the magma can accelerate the maturation of the organic matters and influence the generation and preservation of oil and gas. A thermal modeling of the sheet magma intrusive sutloonlusions: (1) The cooling rate of the intrusive body is very quick, usually within 1Ma; (2) The superheated temperature histories of the host rocks which are equi-distant from the intrusive body are almost the same, whereas the temperature ofthe magma only influences the magnitude of the superheated temperature of the host rocks and does not influence the velocity of heat transfer; (3) The influence on the kerogen maturity of the host rocks are roughly the same over and belowine anefect zone is limited, usually about twice the thickness of the intrusive body. After a study, the thermal evolution patterns of the source rocks which are effected by the magmation are divided into three types, they are near、middle and far thermal source kitchen sub-patterns, and the classification principles and methods of the sub-patterns are also presented.
The purpose of this paper is to introduce a simple and convenient forward method by which seismic shot record can be produced. The theory is based on the cat wonadtheory using Huygens’s principle and forward portion by Berkhout`s point imaging technology. This kind of forward method is not only mature but also simple and convenient in operation. With respect to the inversion using common focus point imaging method, it will be specially presented in other papers,the focus is to get forward shot record by studying the theory of common focus point imaging so as to study inversion by using it.
The Heidun target area is a third class structure unit of Santanghu basin. It was extruded during the period of late YanshanXita ter deformed severely and the structure is very complicated. In order to explore hydrocarbon , the critical task is to get clear understanding of the target area's structure characters. Withthe help of faulting related fold theory and visual computer technology, the 3D seismic data was interpreted. Based on this, it is recognized that fault-bend fold, growth fault-bend fold and compound triangle structural wedge are the main structure styles of the target area.
The output of natural gas is closely associated with thickness, porosity, connectivity of the sand and the ratio of sndToceth conformation, direction, changes and connectivity of sand in special, we have done subtle identification and interpretation of the sand in this field based on previous investigation and studies. The responses of sand in seismic profile usually are high amplitude and low frequency. The beneficial containing natural gas sand of high porosity and connectivity is characterized by low velocity and reversal polarity. But we found that the responses of sand in this field are divers, hestphnomenon of severe inconsistent between synthetic seismogram and the seismic records besides wells. Therefore we cannot identify the sand in this field by uniform mode. We have carried out this work by the way of constraining of many wells, standardizing with many formations and interpreting layer by layer on seismic synthetic records. The present paper introduces our sand identification and its interpretation methods in this field.
In order to suternarrviondtions, it is necessary that water saturation establishment in cores must be any saturation desired and insure water uniformly dispersed, the pore geometry and component of cores unchanged. At present, there are several mainly methods to establish water saturation such as drying method, centrifuge method and displacement method. Seeing that tight gas sands has tight lithologic character and ultra-low water saturation, it is difficult or impracticable that water saturation estaedghs thse methods is less than irreducible water saturation. The paper puts forward a new method of establishing water saturation called spontaneous imbibition method, it can be used to establish water saturation in tight sandstones and has been proved by experiments to be feasible.
Nowadays the fractured horizontal well technology has become an important method for developing the low permeability gas reservoirs around the world, so correctly predicting the fractured horizontal well productivity is essential to the design of the horizontal well development program, and the sensitivity analysis of formation and fracture parameters. A percolation model of the fractured well in low permeability reservoirs was presented in this paper, which includes the coupling of formation percolation and horizontal flow in the horizontal wellbore by using the complex potential theory, potential superposition principle, fluid mechanics theory, as well as the real gas state equations. According to the characteristics of the model, the ioluasabe. Furthermore, some practical examples of the low permeability gas reservoirs in Changqing oilfield were calculated for comparison. The calculation results showed that: (1) The pressure drops in the horizontal wellbore had some effect upon the production performance of the fractured horizontal well; (2) The pressure distribution along the horizontal well was not well-proportioned, (3) not equal for each fracture production. This paper also analyzed those parameters which aff tlbesros and fractured horizontal well's production, such as wellbore radius, horizontal section's length, fracture number and pipe-wall roughness, finally some useful conclusions were obtained.
In this paper the dimensionless pressure distribution and solutions of variable flowing rate in Laplace space under two inner boundary conditions have been researched in double porosity composite and constant pressure at outer boundary reservoir model, the research improves well test analysis t a wpl vlue to the development of corresponding well test analysis software.
The high pressure PVT experiment data of the gas condensate and the oil of oil gas condensate reservoirs in Pen well 5 area is calculated by matching and the fluid composition characteristic parameters, which can suitably describe the phase behavior of the oil gas condensate reservoirs, are determined. According to the physical property of each interval determined by geologic study, the well loc a sreha ad the geological characteristics of the wells, the three dimensional geological model is built. To demonstrate the reasonable exploitation strategy parameter of oil gas condensate reservoirs in Pen well 5, the numerical simulation research of development factors of the reservoirs is done in the six aspects. The research results can conduct the practical development of the oil gas condensate reservoirs.
Due to every gas injection candidate reservoirs having different kinds of affective factors, the factors depend on eachr soad ech other, which bring some difficulties in deciding and evaluating to manager， the evaluation index system and the evaluated range of the index was introduced in the paper, the fuzzy optimum screening model of the candidate reservoir for gas injection and its calculate step was established, On the foundation of obtaining the same reservoir parameter weight which was calculated by fuzzy gradation analysis, the fuzzy optimum screening model which applied to screening the unitian rirga injection was successfully established. The example has proved that this method would rightly evaluate and compare the potential of the candidate reservoir to gas injection.
The extra-low permeability block reservoirs can not be exploited efficiently because of its poor physical property and reservoir damage by water injection. The paper, taking Huayuan oilfield as the case, analyzes the reservoir characters and reservoir damages of extra-low permetyvoen ijection match experiment, scale formation prediction, the medicaments' choose and the acid pretreatment's study is made. These experimental evaluations provide the basic information to inhibit the reservoir damages and optimize the water injection. This study has been well applied in field test.
Aimed at Suizhong 36-1 oilfield of Bohai Bay, which was characteristic of multi-layer, thick oil layers, high permeability and porosity, loosely consolidation of the rocks and the dramatically var inene mabiyaswell as acid absorbability, asimple, effective and practicable diverting acid technique together with the diverting agent suitable to the field was put forward, and the performance evaluation and computer simulation were carried out systematically. Research suggests that this diverting agent, which was soluble in the producing liquids and has no side effects on reservoir, can accomplish reasonable acid diverting of this field successfully. This new technology can effectivelye ob asibution in acid treatment of multi-zone reservoir varied in permeability and improve acidizing effect significantly. The application of the agent can also decrease water cut to some extent. The technique has been widely used in Suizhong 36-1 and other oilfield in Bohai Bay, and yielded desired results. The application of this technique in Bohai Bay was used for reference of acidizing similar oilfield.
The interference well testing theory has been developed in some degree, the theory and analysis method in hoeoerasedso well, and the theory in dual porosity reservoir has been relatively perfect. But, the theory and analysis method of interference well testing in composite reservoir is developing slowly, especially considering wellbore storage and skin factor. So the paper put forward considering the composite reservoir well testing model considering wellbore storage and skin factor, the model with the Laplace transfer was solved, and the corresponding type curve was plotted.
On the base of gray theory and fuzzy mathematics, the optimal decision-making of the block profile modification and displacement project were discussed with the gray association. The study indicated the gray association model can deal with optimal decision-making of project with correlation among element. With the increase semidiameter of the deal with, the water and oil product was improved obviously, but the project was not the best one while considered the fact of water and oil and the cost of project etc.
The sodium clay and AM monomer are blended together ,br tenelacting with initiator and crosslinker at 130℃. In the system of the blending gel the formulation is as follow: sodium clay 6%, AM 6%～7%,initiating agent Y100mg/L～200mg/L and crosslinker J 1%～1.5%.Because of the sodium clay, the gel time is delayed and the thermal stability is enhanced. The intensity of the blending gel is intensively high and the ability of blocking is comparatively good, so as temperature water shutoff agent the system has a good prospect to be use.
Elemental sulfur ,a harmful mass with the process of exploration gerofpoited in the formation, downhole tubulars and wellhead equipments. This always makes well product decrease or equipments be plugged. It, therefore, has great meaning on exploitation of sour gas reservoir that understanding the mechanic of sulfur-solubility. It found that temperature ,pressure and composition of gas are the most important keys influenced the solubility of elemental sulfur in nature gas. If temperature or pressure increased, Solubility of elemental sulfur in natugasas teime, the content of hydrogen sulfide and weight compositions in gas had great effect on solubility of sulfur. All those illuminate the mechanism of elemental sulfur solution in sour gas including both chemical solution and physical solution.
The primary functions of flushing fluid include washing the wall of a well and scouring empty mud cake、slurry oil、oil layer in casing wall, diluting drilling fluid and making its flowing property favorable. Consequently, improve ent efficiency and ameliorate interface hydrophile ability; Improve ceme sh aln rder to make good use of the flushing fluid rational design must be done and we should know its variety、performance criteria、component、mechanism、design requirement and merit rating's instrument、approach、 standard and etc.
The state of carbon dioxide and its effect on corrosion of pipe string for the oil and gas well at high temperature and pressure were theoretically analysed. A new theoretical conception was presented, in which the carbon dioxide mole concentration in the system and its distribution coefficient in the medium of oil and water in the condiiofl pere edefined to describe corrosion procedure of carbon dioxide in the deep stratum and pressure funnel in pipe string when carbon dioxide is in the supercritical fluid state.
After analyzed the failure mechanism of physics exploration hammer, the failure cause of the inner cylinder liner was mainly plastic deformation and eccentric wear, the failure cause of the piston was mainly abrasion on its outside part and fatigue failure on the end plane. The principal mode of abrasion was stuck wearing and abrasive wear. Finally, theilsu pwad to prolong the service life of hammer and some experimental investigation on the heat treatment to piston was also done.
This artical is about a new design notion of the general hydrocyclone which was except to improve the separate efficiency of the hydrocyclone by solving the problems of shortcut flow and circle flow. Under the ground of the flow field theory, a special filtering-net which is called lateral zero velocity veil (LZVV) filtering-net was added in the place of LZVV. The filtering-net was accepted to improve the separate efficiency of the hydrocyclone. The rationality of the improveisst A, he influence of the filtering-net to the flow field and some relational problems were mentioned.
The state of carbon dioxide and its effect on corrosion of pipe string for the oil and gas well at high temperature and pressure were theoretically analysed. A new theoretical conception was presented, in which the carbon dioxide mole concentration in the system and its distribution coefficient in the medium of oil and water in the condition of total pressure were defined to describe corrosion purarox te deep stratum and pressure funnel in pipe string when carbon dioxide is in the supercritical fluid state.
Tax planning may benefit the development of petroleum enterprise, meanwhile it brings about some risk that can not be negligent. The article introduces the definition of tax planning, describes the possible risk in tax planning, and deeply analyzes uncertain factors provoking the risk, at last the measures of prevention of tax planning risk, and has some potential reference value to the real production and management of petroleum enterprise.
