Table of Content

01 December 2005, Volume 26 Issue 6 Previous Issue    Next Issue

For Selected:

Download Citations EndNote Reference Manager ProCite BibTeX RefWorks

Toggle Thumbnails

On Austral-Style Petroliferous Domain AN Zuo-xiang, MA Ji, PANG Qi-wei 2005, 26 (6):  607-611.  Abstract ( 112 )   PDF (993KB) ( 224 )   Save The classification of austral-style petroleum domain is based on previous austral system established by Dr.Weng Wen-bo.The austral system was divided into three petroliferous domains as Australia (India-Australia), Africa (Africa-Arabia) and South America in terms of global plate distribution.It was the three domains that ever made up of Gondwana land together with Antarctica before Mesozoic era, and were then separated from Gondwana land during Mesozoic to Cenozoic, forming Indian Ocean and South Atlantic Ocean as well as Pacific Ocean, along with Tethys closure.Hence, the Paleozoic, Mesozoic and Cenozoic zones over continental nucleus and its circumferences were of both individual feature and sizable superposition.The most typical Persian Gulf basin is characterized by the superposition with these zones one after another.Five types of basins such as intracratonic basin, foreland basin and fold belt, movable continental margin, divergent continental margin and impactogen basin then occurred and the higher deposition velocity of oil zones appear on their sedimentary curves.Oil-gas pools or fields found in Persian Gulf basin possess obvious remigration processes known as a complex petroleum system. References | Related Articles | Metrics

The Changing and Origin of the Carbon Dioxide in Associated Gas of Daqing Placanticline WANG Lian-sheng, GUO Zhan-qian, MA Zhi-hong, CHI Dong-hui, WANG Pu-jun, WANG Shu-xue 2005, 26 (6):  612-613.  Abstract ( 89 )   PDF (241KB) ( 193 )   Save The CO2 content in associated gas of Daqing placanticline has increased greatly since the 1990s, reaching the total amount of 2.87%(V/V) in 2003, increasing about ten times compared with that in the 1980s, and the rising trend will be maintained.By determination of the δ13 C of CO2 in associated gas shows that it is bigger than +3‰ for three samples, indicating that the origin of this CO2 is the pyrolysis of carbonate.The reason of the increase of CO2 content is mostly related with frequency of new-tectonic movement and the rising of heat flow from the deep earth. References | Related Articles | Metrics

Tectonic Model and Its Deformation Featur e of Cenozoic in West Section of Lenghu Structural Belt,Northern Margin of Qaidam Basin CHEN Zhi-yong, WANG Li-qun, CHEN Shu-ping, WANG Zhi-xin 2005, 26 (6):  614-617.  Abstract ( 68 )   PDF (695KB) ( 210 )   Save The 3D seismic information from Structure 4 and Structure 5 in northern margin of Qaidam basin are fine interpreted,integrated with data of surface geological survey and drilling.By determining the structural elements,its tectonic model is developed.Structure 4 and Structure 5 occur as fault-complicated anticlines of S-N trend,with slight difference in structural depth to some extent.Structure 4 is a box-like anticline and Structure 5 an oblique one,but they have different deformation styles in overlying and underlying zones,which shape complex structural superimposition.The transition zone between Structure 4 and Structure 5 occur as faulted and oblique anticline.The study shows that the belt of Structure 4-5 is controlled by both folding and X-style faulting,and the structural style lies on the faulting development.Based on the unconformity and the fault assemblage,the period of forming these structures should be in late Himalayan movement when Lower Youshashan formation was deposited,with compression of SW-NE direction.The formation of these structures is also related with the Jurassic distribution in this area. References | Related Articles | Metrics

Characteristics of petroleum geology in South Poyang Depression ZHOU Song-yuan, ZHENG Hua-ping, PEN Jun, XU Ke-ding, JIANG Wei-shan, LIU Jia-duo 2005, 26 (6):  618-622.  Abstract ( 92 )   PDF (789KB) ( 157 )   Save The South Poyang depression is an overlay basin formed by the Mesozoic-Cenozoic continental basin and the Paleozoic Mesozoic marine-transitional basin, characterized by upper tensile structure and lower compressive structure.The Jiuling Nappe (slide) System in lower tectonic layer overrides (slides) from north toward middle-south part of the depression, while Guanmaoshan overthrust system moved to north forms a ramping front belt which is a favorable zone for petroleum exploration conserved in Permian.The evolution of the Mesozoic-Cenozoic basin is controlled by the paleo-tectonic framework and Ganjiang faulting belt in the mid-episode of Yanshan movement.The source rocks are developed in Permian, and the bark-like coal of Longtan formation (P2l) belongs to a high quality of coal derived-oil source rock, with multiple types of traps dominated by block structural traps and sandstone lithologic traps in the depression.It is concluded that the most favorable type of hydrocarbon accumulation is the complex lithologic-structural trap with both source and reservoir in Longtan formation that underwent the secondary hydrocarbon generation and late-stage hydrocarbon accumulation in the depression. References | Related Articles | Metrics

Oil Source Analysis and Explor ation Prospect of Lunnan Field in Tarim Basin SHI Hong-xiang, XU Zhi-ming, LIN Feng, WANG Ting-dong 2005, 26 (6):  623-626.  Abstract ( 81 )   PDF (341KB) ( 218 )   Save The geochemistry of Lunnan crude is comprehensively studied.This paper presents that Lunnan crude primarily originates from the Cambrian-Lower Ordovician source rocks, combined with the structural development history, the source rock evolution history and oil gas distribution characteristics.So the Cambrian-Lower Ordovician strata should be taken as major source rocks for petroleum exploration in Tarim basin instead of pinning our hope on search for giant oilfield in Middle-Upper Ordovician strata as major source rocks in order to avoid the existed misdirection. References | Related Articles | Metrics

The Structural Features of Kongquehe Area in Tarim Basin TIAN Na-xin, YU Ming-de, TU Zhi-min, MA Yu-chun 2005, 26 (6):  627-631.  Abstract ( 111 )   PDF (445KB) ( 248 )   Save The structural features are complicated in Kongquehe area because of the influences of Kuluktag faulted uplift and multi-stage tectonic movements.The faults that affect the area most are Kongquehe fracture, Baliying fracture, Weili fracture and Weimake-Kaiping fracture.The area had undergone such evolution stages as passive borderland basining, squeeze-retrograde nose-like swelling, cratonic inner sagging, intracratonic basining and para-foreland basin.Late Caledonian tectonic movement formed the basic structural configuration of the Lower Paleozoic; Yanshan movement regenerated Palaeozoic structures and shaped Jurassic structures; Himalayan movement made the area developed as a para-foreland basin.Large-scale nose-like swells were developed during the Palaeozoic era, while the Mesozoic was dominated by the faulted-anticline traps with thrust belt.The trap can be divided into four types and subdivided into ten kinds, and three structural styles were developed in this area. References | Related Articles | Metrics

Petrologic Featur e and Sedimentary Environment of Yanchang Coal in Ansai Oilfield XUE Chun-yan, YAO Su-ping, HU Wen-xuan 2005, 26 (6):  632-636.  Abstract ( 94 )   PDF (470KB) ( 287 )   Save The organic petrologic characteristic of coal is one of good assistant indices.The organic petrologic study of Yanchang coal and carbonaceous shale of Ansai oilfield in Ordos basin indicates that the macroscopic petrologic characteristic, material and composite relation of the biogenic rock as well as the occurrence of organic matter can be used to better reveal the marsh paleo-geographic environment and depositional site originated by the coal and carbonaceous shale.Also, the marsh environment is classified into autochthonous terrestrial peat bog, blanket bog, moss bog and allochthonous floating bog.These can be as a significant guide for determination and evolution of paleo-lake strandline at Yanchang series of Triassic and classification of the depositional facies. References | Related Articles | Metrics

Analysis of Oil Accumulation Efficiency of Upper Ganchaigou Formation of Neogene in Western Qaidam Basin FAN Yuan-fang, FENG Yong, YAO Jian 2005, 26 (6):  637-639.  Abstract ( 87 )   PDF (351KB) ( 126 )   Save Upper Ganchaigou formation of Neogene is the major source rocks in western Qaidam basin.Its geochemical feature is studied on the basis of previously studied results.The organic carbon content of 0.3% cut-off value is determined, by which the hydrocarbon generating efficiency of 1.23% is offered, being obviously lower than 11.5% of Jurassic formation of Cook Gulf area in Alaska of America given by Leslic B.Magoon in 1994.The study shows that the hydrocarbon may be accumulated in the non-structural traps to be found.These traps should consequently be the important targets for further exploration in the studied area. References | Related Articles | Metrics

Numerical Simulation of Tectonic Stress Field during Himalayan Movement in Southern Margin of Junggar Basin ZHOU Feng, MEI Lian-fu, LIU Lin, TANG Ji-guang, YAN Shu-lan, LUO Ji-chun 2005, 26 (6):  640-643.  Abstract ( 91 )   PDF (907KB) ( 352 )   Save By using SSFM simulator of finite element method, this paper presents the simulation of tectonic stress field in the southern margin of Junggar basin during Himalayan movement.The results show that the southern margin of Junggar basin during Himalayan movement is in compressional environment on the whole and characterized by compressive stress.The high value zone of maximum principal stress is mainly distributed in the north Tianshan mountain and its front, and the low value zone of it is at Bogda mountain.From south to north at the west section of the southern margin of Junggar basin, the high-to-low stress trend appears, but at the east section the stress trend is from low to high in circle way from Bogda mountain to surroundings.The minimum principal stress trajectory assumes zonal distribution with trend NWW at the west section and arch distribution at the east section, similar to the faulting strike and major structural line.At last, this paper discusses the dynamic mechanism of forming stress field of the southern margin of Junggar basin during Himalayan movement by study of these stress fields. References | Related Articles | Metrics

Reservoir Featur e and Distribution Prediction of East Benbutu Area in Yanqi Basin NIE Ming-long, SUN Bai-nian, LIU Zhen-wang, ZHANG Zhi-qiang, HOU Qing 2005, 26 (6):  644-646.  Abstract ( 81 )   PDF (727KB) ( 182 )   Save The reservoirs of east Benbutu area are mainly distributed in the lower member of Sangonghe formation and the upper member of Badaowan formation of Lower Jurassic in Yanqi basin.Based on the payzone division and correlation, the lithologic and physical characteristics of the Ⅰ-Ⅳ payzones are studied.The lateral changes of payzone thickness and physical characters in the reservoirs are predicted with logging constrained seismic inversion, and the payzone distribution of 3D is described.The result shows that there exist the features of poor sorting, low shale content and poor physical properties in the reservoirs, which belong to low-porosity and extra-low permeability reservoirs.The payzone sands are thicker in the structural high and better in physical property, but become thin and poor towards the structural low.It is concluded that the southeastern Wellblock Tu-301 is well-developed reservoir rock area and favorable for further petroleum exploration. References | Related Articles | Metrics

Establishment and Significance of Reservoir Thickness Spectrum YONG Xue-shan, WU Sheng-he, LIU Jun-ying, WU Hui-liang, GAO Jian-hu 2005, 26 (6):  647-649.  Abstract ( 90 )   PDF (534KB) ( 189 )   Save The study of reservoir thickness has direct and close relations with gas-oil prospecting and exploitation.The analysis of vertical and horizontal changes of reservoir thickness is of great significance for finding out lithologic oil-gas pools.This article puts forward a time domain-thickness spectrum method for reservoir imaging based on improved wavelet.The single-trace analysis method can be used to produce a seismic trace spectrum for analyzing vertical changes of reservoir thickness.When we analyze other seismic traces along seismic profiles, the horizontal changes of reservoir thickness can also be studied.Testing results show that this is a visual and high resolution method and has a value for application. References | Related Articles | Metrics

Hydrocarbon Geochemical Indices Selection by Grey Correlation Analysis LI Shui-fu, HE Sheng 2005, 26 (6):  650-652.  Abstract ( 69 )   PDF (332KB) ( 195 )   Save With the development of petroleum geochemistry and improvement of modern analytical technology, more and more biomarker parameters of petroleum are available.This paper selects 30 biomarker indices from 27 oil samples in Nanyang depression on the basis of some well known biomarker indicators and using the grey correlation analysis, and classified into three types related to original organic matter, organic matter maturity and both of them.Such new geochemical indices as m(β-drimane)/m(α+β-drimane),m(βα-pregnane)/m(αβ-pregnane), m(oleanane)/m(gammacerane), m(8,14-secohopane C29)/m(C30) are proposed in this paper.They will support the in-depth study of the molecular parameters in geochemistry. References | Related Articles | Metrics

Recognizing and Suppressing Ground Roll Wave with Average Energy Method WANG Zai-min, LI Li, ZHU Peng-fei, ZHANG Zhong-hu, GUO Hong-xian, JIANG Li 2005, 26 (6):  653-655.  Abstract ( 77 )   PDF (392KB) ( 174 )   Save Ground roll wave has characteristics of strong energy, low frequency and slow attenuation.In the low band of wavelet transform,energy of ground roll wave is normally greater than the average energy in overall band of seismic reflection event, which is regarded as the discrimination criterion for it.Through definition range of the window and the suppressing threshold, the damage of seismic reflection signals with low frequency can be avoided.By using narrow band and equal distance wavelet transform and average energy method, the ground roll wave can be recognized and suppressed better, hence obtaining good results. References | Related Articles | Metrics

Sour ce Analysis of Reservoir Sands in Microscopic Feature—An example of Shanle area in Tuha basin LI Sen-ming, LI Peng, SUN Hui-ping, WANG Tian-peng, TAO Hong-zhou, NI Lian-bin 2005, 26 (6):  656-658.  Abstract ( 81 )   PDF (344KB) ( 161 )   Save The petrologic make-up and the heavy mineral feature analyses show that J2x1-2 reservoir sands of Shanle area in Tuha basin are good in sand compositional maturity with a typical rock assemblage dominated by dacite, dacite liparite, intermediate-basic extrusive rock and intermediate-basic tuff debris, but poor in sand structural maturity and sorting with angular-subangular quartz clasts; the sand heavy minerals appear in an unstable typical mineral association, and the diagenetic environment is weak.Integrated with macro-and fine formation correlation and depositional setting analysis, it is clarified that the J2x1-2 reservoir sands belong to sedimentary system of the north sources.This paper suggests that the source analysis of foreland basin should be made considering micro-stratigraphic feature, environment conditions, etc., which could be as a guide for similar source supply studies in the future. References | Related Articles | Metrics

Characteristics of Ground Water Table Reservoir LIN Shao-Hua, WEI Rong-Fang, JIANG Bing, XUE Ping, CHANG Yu-Qin 2005, 26 (6):  659-660.  Abstract ( 92 )   PDF (187KB) ( 136 )   Save A ground water table reservoir is formed by complex processes of multiple geologic factors.Comparing with conventional reservoirs, this kind of reservoir is characterized by dynamic migration, energy-free, high porosity and permeability, high oil column, enormous geologic reserves, and oil varying from heavy to light.In consequent structural and deposit evolution, it tends to shape heavy oil-sealing reservoir with highly hidden nature.Qiketai reservoir in Tuha basin is a typical ground water table reservoir.In analog basins in geologic conditions, there should be similar reservoirs.For the enormous geologic reserves that normally occur, this reservoir has high value for exploration. References | Related Articles | Metrics

Study of Horizontal Fr acturing-Assisted Steam Flooding Technology and Field Pilot Test SHAO Xian-jie, ZHU Si-jun 2005, 26 (6):  661-663.  Abstract ( 100 )   PDF (330KB) ( 196 )   Save By physical modeling and numerical simulation, the characters of horizontal fracturing-assisted steam flooding technology and oil incremental mechanism is summarized, that is, using horizontal fracture to control the steam overlaying rate and delay the steam breakthrough time can be effectively enhance the vertical sweep efficiency.According to characteristics of the reservoir, some new technologies and methods have been successfully applied in the pilot test, such as reasonable optimization of steam injection parameters, dual-fracture technology, dense perforation technology and steam fracturing technology.These critical technologies and methods allow the production rate, the cumulative oil-steam ratio and ultimate recovery factor of the shallow-thin and extra-heavy oil by steam flooding process to reach 17.4%, 0.21 and 37.7%, respectively. References | Related Articles | Metrics

Calculation of Density Correction-Based Pseudo Critical Parameters of Sour Gas WANG Zhou-hua, GUO Ping, ZHOU Ke-ming, ZHANG Di-hong, WANG Li, GAO Hui-jun 2005, 26 (6):  664-666.  Abstract ( 98 )   PDF (339KB) ( 164 )   Save The pseudo critical parameters of natural gas are the gas-related fundamental calculation data.The pseudo critical parameters of sour gas are calculated mostly by Kay rule and Wichert-Aziz correction, but the sour gas density-based method has not been published at home.This paper collected 93 sour gas samples from several gas fields at home and broad and established a new equation for calculation of the pseudo critical parameters of sour gas integrated with the experimental results.Also, the deviation factors (Z) of sour gas and conventional gas for H2S and CO2 are calculated by the new equation.Compared with the experimental results obtained by Kay rule, Wichert-Aziz correction model and Standing method, the result shows that the new equation is fit for sour gas and the accuracy is higher than Kay rule and Standing equations.However, for conventional gas with low molecular weight, the accuracy of Standing method is the highest. References | Related Articles | Metrics

Multifactor Analytical Model for Natur al Decline Rate in Waterflood Field LI Ju-hua, GAO Wen-jun, YANG Yong-li, JIANG Tao 2005, 26 (6):  667-669.  Abstract ( 89 )   PDF (286KB) ( 207 )   Save Based on the definition of production decline rate, the multifactor analytical model for composite decline rate is developed, which discusses affecting factors such as the startup well number, water cut, producing fluid thickness, pressure, relative production index, well spacing density, skin factor, etc.Integrated with the correlation between natural and composite decline rates as well as the characteristic of production testing data, the model for natural decline rate is established.The model can be used to analyze accurately the effect of individual interrelated factor on production decline rate, support regulative countermeasures and modify the natural decline rate in an oilfield.The case study indicates that this model is effective in practice and good for popularization. References | Related Articles | Metrics

Char acteristic Par ameter Analysis of Gener alized Arc-Tangent Distribution Production Decline Equation ZHANG Yuan-ping, GAO Wen-jun, ZHAO Xiao-ping, SUN Hui-ping, PAN Hong-fang, WANG Lan 2005, 26 (6):  670-672.  Abstract ( 90 )   PDF (295KB) ( 201 )   Save The analysis of characteristic parameters from generalized arc-tangent distribution production decline equation shows that if C= 0, the decline equation can be transformed into hyperbolic decline equation of Arps decline equation; if C=0 and m=-1, the decline equation can be transformed into exponential decline equation of Arps decline equation; if C=0 and m→∞, the decline equation on one hand can be directly transformed into harmonic decline equation of it, and on the other hand can be approximately transformed into Logistic production decline equation; if m=0, the decline equation is the arc-tangent distribution production decline equation.Based on these studies, the solution to the generalized arc-tangent distribution production decline equation is presented in this paper.The good effect has been obtained from the case application and is worth popularizing. References | Related Articles | Metrics

The Modification and Improvement of Webull Production Decline Equation BAI Qing-hua, WANG Yi-cai, JU Ya-ming, GAO Wen-jun, ZHANG Peng-yi, WANG Wen-xia, ZHAO Xiao-ping 2005, 26 (6):  673-674.  Abstract ( 90 )   PDF (150KB) ( 141 )   Save In order to solve the problem that is no initialization decline rate in Webull production decline equation when b rangesfrom 0 to 1, modification of the equation is raised.The standard equation and calculated methods of undetermined parameters are presented.The modified equation allows wider range and coverage, which can not only be used to describe the production decline when decline rate shows monotone decreasing, and also describe the production decline when decline rate shows monotone increasing or is a constant value.The good effect for application of the modified equation has been obtained in Tuha oilfield. References | Related Articles | Metrics

Reservoir Fluid Property Identification with Support Vector Machine Method YU Dai-guo, SUN Jian-meng, ZHANG Zhen-cheng, WU jin-long 2005, 26 (6):  675-677.  Abstract ( 113 )   PDF (253KB) ( 208 )   Save The Support Vector Machine (SVM) Method is first introduced into reservoir fluid property identification, by which the models for identifying oil, gas and water are developed through study of the complex relations between measured logging data and comprehensively interpreted parameters about reservoir fluids.The applied results indicate that SVM method is a feasible, effective and higher accurate way for well logging interpretation of reservoir fluids as a new, simple and reliable method with high accuracy. References | Related Articles | Metrics

The analysis and application of the nodal system of gas well QIN Guo-wei, GUAN Jun 2005, 26 (6):  678-680.  Abstract ( 98 )   PDF (426KB) ( 204 )   Save According to the actual production conditions, the mathematical model of nodal system analysis of the gas wells is established and the mathematic expressions are proposed.It can be used to calculate the gas yielding amount of different tubing diameters and the pressure loss for each segment and to predict the gas productivity based on the performance curves of gas wells.It can also be applied to do many other works for gas wells such as system's index prediction and parameter optimization, etc.The calculation and analysis are conducted by means of the field data from gas well Wen-23 in Zhongyuan oilfield.The calculated results accord basically with the real indices and parameters. References | Related Articles | Metrics

Study of Microscopic Oil-Water Displacement Mechanism of Low-Permeability Reservoir —An example of Chang 82 Reservoir in Wellblock Zhuang-19 of Xifeng oilfiled FU Xiao-yan, SUN Wei 2005, 26 (6):  681-683.  Abstract ( 80 )   PDF (432KB) ( 217 )   Save Chang-82 reservoir of Well block Zhuang-19 in Xifeng oilfield is of very low permeability and poor petrophysical properties, belonging to a low-permeability reservoir.The water-oil displacement mechanism and efficiency-affected factors in the studied area are analyzed systematically using real sandstone micro-model for water-oil displacement experiment (including single model and combination model), offering the realistic and visual percolation characteristics of fluids and remaining oil distribution in the process of water-oil displacement.This study can be as a guide for water flood scheme design of such a well block and other similar reservoirs. References | Related Articles | Metrics

Study of Remaining Potential Stimulation in Hubuzhai Block Gas Pool, Zhongyuan Field LIAO Jia-han, TAN Guo-hua, CUI Da-qing, FANG Zhi-wei, YANG Yong-chao 2005, 26 (6):  684-685.  Abstract ( 75 )   PDF (318KB) ( 141 )   Save According to the characteristic of Hubuzhai complex fault block gas pool, the fine structure, reservoir rock and sand distribution of it are studied.The remaining gas distribution is reconsidered through fine gas pool numerical simulation.The regularity of the remaining gas distribution and measures for further development of the remaining gas are presented.And the field test shows better results. References | Related Articles | Metrics

Calculation of Fluid Diffusion Coefficient in Porous Medium CHEN Xing-long, LI Zhi-ping, QIN Ji-shun 2005, 26 (6):  686-688.  Abstract ( 169 )   PDF (412KB) ( 446 )   Save The fluid diffusion coefficient in core can be deduced from the mass diffusion equation, but some mass concentration as a key basic parameter of fluid should be obtained in core lab.The calculation of fluid diffusion coefficient is restricted for little volume of the fluid by conventional core test, so one-dimensional mathematical model of mass transfer diffusion is developed, and method of combining numerical simulation with experimental result is put forward.With this method, just one-time measurement of the average mass concentration of high volume of fluid is conducted, followed by tuning and match, the diffusion coefficient is offered.The modeling result shows that the proper diffusion coefficient is influenced by mass concentration, type, flowing velocity of fluid and rock permeability, etc.But the limit-range change of a solution diffusion coefficient has little effect on the distribution of fluid mass concentration.For this reason, the diffusion coefficient is normally assumed to be a constant. References | Related Articles | Metrics

Application of Higher Order Statistics to Seismic Inversion NING Song-hua 2005, 26 (6):  689-691.  Abstract ( 84 )   PDF (561KB) ( 371 )   Save Seismic inversion is an effective method for study of reservoir distribution, but it can hardly satisfy the demand when available seismic data are in low resolution.Whether the resolution of inversion data is high or low depends on the seismic wavelet to a large extent.This paper proposes the higher order statistics method by which the seismic wavelet taken is more similar to the real seismic wavelet taken by the conventional method.By comparison between the two methods, the seismic data inversed with higher order statistics method are obviously improved in seismic data continuity and resolution, showing that it has a good application potential for improving seismic data resolution. References | Related Articles | Metrics

Application of Pool Size Sequence Method to Pr ediction of Petroleum Resources in Jinhu Sag SONG Ning, WANG Tie-guan, LIU Dong-ying, GAO De-qun 2005, 26 (6):  692-694.  Abstract ( 74 )   PDF (357KB) ( 198 )   Save The scale of oil-gas resources undiscovered in mature hydrocarbon province is greatly paid attention to.This paper presents a pool size sequence method and estimates the remaining petroleum resources in Jinhu sag with the total amount of the resources of 10 802×104 t and their distribution in nearly 159 reservoirs, of which the undiscovered resources amount to 4 038×104 t, distributing in about 58 reservoirs.Although it has a higher extent of exploration in this area, there still exist some potential for petroleum prospecting.A great number of medium-small-sized pools will be as key targets for further exploration in the future.The pool size sequence method can be applied to make a prediction of the petroleum resources by way of simple procedure, and is of a broad application prospect. References | Related Articles | Metrics

MILU-ORTHOMIN Method for Black Oil Model LI Zhong-feng, HE Shun-li, MEN Cheng-quan 2005, 26 (6):  695-697.  Abstract ( 87 )   PDF (297KB) ( 300 )   Save A numerical simulation at last comes down to calculation of a number of large linear equation groups, and an excellent simulator should be provided with advantages of wide application and rapid convergence.As implicit pressure and explicit saturation (IMPES) method is selected to calculate black oil model and the bottom-hole pressure is introduced, the coefficient matrix of pressure equation becomes bordered seven-symmetrical matrix.The modified incomplete factorization (MILU) -orthogonal minimization (ORTHOMIN) method can be used to calculate large asymmetric sparse matrix as one of the pretreatment conjugate gradient methods.MILU method keeps the sparse character of sparse matrix and saves the storage space, while ORTHOMIN method accelerates the rate of iteration convergence obviously.According to the MILU-ORTHOMIN method, the horizontal single well simulator is programmed.The IMPES and the implicit wellbore pressure method are employed in this paper.As the same iteration accuracy rate is selected to solve the same problem, it is found that the MILU-ORTHOMIN method makes the convergence speed increased by 100 times compared to that of normal Gauss-Seidel method (asynchronous iteration). References | Related Articles | Metrics

A Method for Calculation of Aquifer Size in Thin-Layered Bottom-Water Sandstone Reservoir MA Shi-gang, CAO Wen-jiang, SHI Guo-xin, LU Jian-guo, XU Duo-wu, CHEN Hao 2005, 26 (6):  698-700.  Abstract ( 71 )   PDF (273KB) ( 195 )   Save Based on the special geologic and hydrodynamic features, the conventional material balance equation is modified.The hydrocarbon and bottom water underlying oil zone are considered as oil reservoir system; water zone out of oil area as water system, by which the material balance equation for thin-layered bottom water reservoir is established.Then common edged-water influx model is used to calculate aquifer size of this type bottom-water reservoir.Also, in order to validate the reliability of this method, 3D reservoir numerical model for bottom water or aquifer is developed and the correlation study of numerical simulation is conducted.The result shows that the bottom water or aquifer size predicted by the two methods is similar to each other, indicating that the method given by this paper is simple, reliable and practicable for use. References | Related Articles | Metrics

Application of Square Array of Geophone to Desert Tazhong Area, Tarim Basin WEI Dong, NI Liang-jian, TIAN Yu-dong 2005, 26 (6):  701-703.  Abstract ( 85 )   PDF (175KB) ( 185 )   Save The signal-to-noise ratio of r is low in Tarim basin. The interference wave is one of the main factors affecting the deep layer signal-to-noise ratio. Because of complexity of the geologic conditions of the surface and underground in Tarim basin, the noisy type and intensity are varied in different surface structures, different sand dune appearances and different shooting conditions. Hence, the key for deep seismic prospecting is how to reduce the noises and improve the effective weak signals in deep layer. On the basis of analysis of the interference wave characteristic and the quantitative estimation of the signal-to-noise ratio from seismic data, this paper demonstrates the acquisition parameters from the seismic prospecting, presents the method for improving the signal-to-noise ratio, which will play a significant part in accelerate oil-gas exploration in Tarim basin. References | Related Articles | Metrics

Application of Gr ey Theory to Prediction of Oil-Gas Operation Cost of Karamay Oilfield SUN Xu-guang, ZHANG Zhao-xin, BAI He-xian, SHEN Qi-mei, LI jie 2005, 26 (6):  704-706.  Abstract ( 85 )   PDF (269KB) ( 251 )   Save The prediction of oil-gas operation cost is the first step of cost budget and control.This prediction is normally made by using level method and correlation analysis method, but the results from them have some difference with real situation, which is unfavorable for the cost management of modern enterprises.This paper analyzes the grey system model and application realm, it is preliminarily considered that affecting factor, composing environment and system for oil-gas operation cost accord very much with grey system model and belong to grey system matter.In addition, this paper introduces the single serial one-order linear performance model of grey theory and the calculation method of model precision verification and presents the yearly operation cost prediction by taking composite unit operation cost of Karamay oilfield as an example.The result shows that it basically accords with changing regularity of the oil-gas operation cost of Karamay oilfield. References | Related Articles | Metrics

Micro Percolation of Hydrocarbons and Formation of Sumptomatic Minerals in Oil-Gas Pools GAN Gui-yuan, YU Rui-juan, CUI Jun 2005, 26 (6):  707-710.  Abstract ( 82 )   PDF (286KB) ( 283 )   Save The micro percolation of hydrocarbon group in oil-gas pools, of which light hydrocarbons (C1-C5) and non-hydrocarbons (H2S,CO2, H2, CO, etc.) along pore-fissure system in depositional strata towards the earth surface can result in variation of geochemical environment in the system in depositional strata on the oil-gas pools.By interaction between the percolated hydrocarbon compositions and the rock components around the pore-fissure system, the sumptomatic minerals are formed.Up to now, the sumptomatic minerals valuable in field application are pyrite, magnetite, magnetic pyrite and limonite formed by substances like H2S and bivalent iron in deposits.According to their distribution in upper part of reservoirs, the sumptomatic minerals can be applied for petroleum exploration.Hence, the method of sumptomatic minerals can be used for forecasting oil/gas-bearing reservoir underlying the stratum not drilled in well, and for re evaluating the oil/gas-bearing conditions of old wells with low-resistivity pay zones. References | Related Articles | Metrics

Novel Progress on Sour ce Corr elation of Biodegradation Crude Oil NI Chun-hua, BAO Jian-ping, WANG Peng-hui, ZHANG Bao 2005, 26 (6):  711-714.  Abstract ( 87 )   PDF (254KB) ( 196 )   Save The idea and principle of oil and source rock correlation and the identification of crude oil biodegradation degree are briefly described.The new progress of the application of the correlation of oil and source rocks about biodegraded crude oils at home and abroad is summarized.It is considered that the corresponding methods should be taken according to the different biodegradation degrees in practical work so that provides some beneficial enlightenment for petroleum exploration and development.. References | Related Articles | Metrics

Petroliferous Property in Evaporitic Rocks and Sedimentary Basins XU Wen-shi, YU Xing-he, LIU Ni-na, JIANG Hui, ZHANG Guang-quan 2005, 26 (6):  715-718.  Abstract ( 113 )   PDF (691KB) ( 373 )   Save Evaporates normally occur in large-scale petroliferous basins in the world, so there exist closely relations between evaporates and petroliferous basins.This paper discusses the relations among evaporates, source rocks, oil-gas caprocks, oil-gas traps, oil-gas migration and accumulation.The study shows that evaporates act as protections for organic matter in basins, parts of them are as good source rocks; evaporates are effective caprocks and of fine plasticity and fluidity, thus providing good systematic networks and multiple trap types for oil-gas migration and accumulation; the overpressure in the bottom of evaporates tends to offer a driving force for secondary migration of hydrocarbon fluids.It is concluded that evaporates play an important role in hydrocarbon generation, migration, accumulation and preservation in sedimentary basins, and have effects on petroliferous property in the sedimentary basins. References | Related Articles | Metrics

Recovery Paleosalinity in Sedimentary Environment —An example of mudstone in Shuixigou group, southwestern margin of Turpan-Hami basin WANG Min-fang, JIAO Yang-quan, WANG Zheng-hai, YANG Qin, YANG Sheng-ke 2005, 26 (6):  719-722.  Abstract ( 187 )   PDF (293KB) ( 345 )   Save The paleoaqueous environment of Shuixigou group deposit in southwestern margin of Turpan-Hami basin is predicted by using Sr-Ba, B, K/Na and phosphate methods.The results show the fresh-water environment in the period of Shuixigou group with Sr/Ba ratio of less than 1 and B content ranging from 12.30ppm to 64.20ppm, and paleosalinity from 2.28‰ of J1b to 2.23‰ of J1x, averaging 2.07‰.Also, the other methods to recover paleosalinity in sedimentary environment are discussed and their limitations are presented in this paper. References | Related Articles | Metrics

Review of Horizontal Well Productivity Formulae Study GAO Hai-hong, WANG Xin-min, WANG Zhi-wei 2005, 26 (6):  723-726.  Abstract ( 125 )   PDF (300KB) ( 240 )   Save Wide application of horizontal drilling at home and abroad allowed it to be concerned about and focused on its productivity formulae studies.Since 1940s, a series of related formulae have been proposed, with more and more practicable usage after continuous modification.This paper reviews the progress of the horizontal wells' productivity formulae and methods studies, and presents the simplified conditions and applied ranges for the various formulae.Finally, based on the imperfections of them, the suggestions for further studies are given herein. References | Related Articles | Metrics

A Probe of Theory of Petroleum Origin ZHANG Jing-lian, ZHANG Hu-quan 2005, 26 (6):  727-731.  Abstract ( 120 )   PDF (283KB) ( 221 )   Save In just a few years after the beginning of 21th century, the arguments against the organic origin theory have been kept going.The studies of inorganic petroleum origin abroad (e.g.America, Russia, etc.) have been made in progress.The in-depth analyses of some fundamental issues in petroleum geology about origins of gypsum-salt, dolomite and clay mineral, etc.have been conducted.The relationship among deep fluids, mantle plume and hydrocarbons is beginning to arouse more attentions.The more important thing is that the inorganic petroleum origin theory has been applied to the practices for oil-gas exploration at home and abroad for prediction of targets of hydrocarbon prospecting to come.It is concluded that the modern concept of inorganic petroleum origin has gradually been formed. References | Related Articles | Metrics

The Principle of Rock Porosity Invariability in Primary Deformation LI Chuan-liang 2005, 26 (6):  732-734.  Abstract ( 120 )   PDF (169KB) ( 267 )   Save There exist two typical deformations for rocks:primary deformation and structural one.Tight media mainly perform primary deformation in stress process with constant porosity, while loose rocks mainly perform structural deformation with porosity changing.Reservoir rocks are tight media, which deformation process obeys the principle of constant porosity in primary deformation. References | Related Articles | Metrics

The Geologic-Economic Standard for Assessment of Petroleum Resources I.V.Filimonova, U.G.Yeriaomin 2005, 26 (6):  735-738.  Abstract ( 65 )   PDF (225KB) ( 185 )   Save Based on the recent-year experiences, the trend of existing assessment standards and the prediction of future petroleum resources, this paper presents the method for evaluation of utilization benefit of petroleum resources and proposes three basic principles for geologic-economic assessment of petroleum resources such as the popular demand principle including reasonable exploitation of oil-gas reservoirs; the full utilization principle that has been adopted by the law, which may decide the long-term economic benefits, containing rational use of petroleum resources and capital construction funds, manpower and materials; and the profit principle of oilfield development applied for determination of reasonable goals for oilfield development according to complicated market conditions at home and abroad in order for obtaining the maximum profit.Carrying out these principles can assure the long-term and stable development of petroleum industry, add profits of oil-gas field and absorb more funds, thus protecting the domestic long-term geologic-economic benefits through out the world. Related Articles | Metrics