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01 January 2019, Volume 33 Issue 5 Previous Issue    Next Issue

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Genetic Mechanism of Overpressure Large Gas Field (Reservoir)An example from Kuqa depression in Tarim basin FENG Songbao 2012, 33 (5):  1-1.  Abstract ( 174 )   PDF (300KB) ( 317 )   Save Related Articles | Metrics

Relationship Between Sedimentary System and OilGas Enrichment in Sha3 Member in Western Gubei SubSag in Bohai Bay Basin LI Qitao 2012, 33 (5):  1-1.  Abstract ( 50 )   PDF (300KB) ( 206 )   Save The Sha?3 member (Es3) in western Gubei sub?sag in Bohai Bay basin mainly develops fan delta, slump turbidite fan, inshore underwater fan and lacustrine sedimentary systems. The development of fan delta and inshore underwater fan are of successive and stage nature, and these fans develop in weakening trend. The hydrocarbon accumulation in this area is mainly controlled by sedimentary system. The mature source rocks were formed in the lacustrine environment, and reservoirs with good source?reservoir?cap rock assemblage are commonly found in each type of sedimentary system. The lithologic trap controlled by sedimentary system is main type of traps, followed by fault?screened trap. Also, it is recognized that the short distance of petroleum migration, good transport condition of matrix sand body and single petroleum migration and accumulation modes should make the lithologic reservoir become the main target for petroleum exploration in this area Related Articles | Metrics

XType Conjugate Normal Fault in Qiongdongnan Basin and Its Significance in OilGas Exploration HE Yongyao1, WANG Yingmin1, QING Yuanhua2, YANG Guojun3 2012, 33 (5):  1-1.  Abstract ( 61 )   PDF (300KB) ( 241 )   Save X?type conjugate fault is a typical combination style of normal faults. There are two sets of such a fault in Qiongdongnan basin,mainly found in inner sag and marginal swell. This paper discussed its formation mechanism and evolution pattern in view of its section feature and space combination style, combined with previous case studies and simulated experiment results. It is recognized that this X?type conjugate normal fault in this basin is formed under the NW pure shear process, and the formation of each group of conjugate fault system is of synchronism and the combination styles are related with the maximum tensile stress orientation, the ancient landform and their boundary conditions. Their existence suggests that Qiongdongnan basin underwent two times of such a shear process. The X?type normal fault not only serves as hydrocarbon migration pathway, but also improves the quality of reservoir rocks. It is indicated from analysis by ant tracking technique that X?type conjugate normal faults could exist in interior of ancient basal buried hill in this basin, so the buried hill basement reservoir could be the important domain for further petroleum exploitation in this basin Related Articles | Metrics

Thrust Fault Activity and Hydrocarbon Migration and Accumulation in Thrust Fold Belt in Southern Margin of Junggar Basin YANG Geng, LI Wei, LI Benliang 2012, 33 (5):  1-1.  Abstract ( 84 )   PDF (300KB) ( 552 )   Save The thrust fold belt in southern margin of Junggar basin has been still active since the Cenozoic era, and the hydrocarbon exploration in this area must focus in present thrust structural belt rather than ancient one. Based on available surface surveys and 2D/3D seismic data interpretations, the dip angles of thrust faults in this belt most range from 30°±5° to 50°±5°. The stress analysis shows that intersection angle between the principal stress and the fault is about 30°±5°, which means the maximum/the minimum principal stress ratio is the minimum, there exists the maximum fluid pressure, at which the fluids around the fault may flow along the maximum principal stress orientation,the faults become the main pathway of fluid migration. When the intersection angle is about 50°±5°, the reactivated faults need higher fluid pressure, resulting in that the sealing of the fault is relatively better. Under the tectonic compression, the thrust fault extends toward the north,in which the detachment layer of fault is mudstone or shale of the Paleocene Anjihaihe formation, which forms much higher tectonic overpressures in this layer. The sandstone horizontal permeability of the Ziniquanzi formation underlying Anjihaihe formation is much higher than its vertical permeability, which is helpful to becoming favorable reservoirs, being major target zones for petroleum exploration in this area Related Articles | Metrics

Reef Flat Complex Sedimentary Characteristics of Middle Ordovician Yijianfang Formation in Bachu Area, Tarim Basin XU Kang, LIU Sitong, YU Bingsong 2012, 33 (5):  1-1.  Abstract ( 64 )   PDF (300KB) ( 34 )   Save The Ordovician reef?flat complex is one of major oil?gas bodies in carbonate reservoirs in Tarim basin. The occurrence, reef building organisms and sedimentary facies changes of the complex were probed by analyzing characteristics of the ancient geographical setting, petrology, sequence, sedimentary facies, paleontology and geochemistry It is found that the complex is mainly developed in platform marginal facies of member?2 of Yijianfang formation of the middle Ordovician; the reef building organisms are dominated by the tray sort,followed by the sponge. δ13C and δ18O values fluctuations mean this sedimentary stage of Yijianfang formation belongs to sequence from ingression to regression with the relatively stable sea?level changes Related Articles | Metrics

Provenance Analysis of Jurassic Sangonghe Formation in Hinterland of Junggar Basin ZHANG Yuejing 2012, 33 (5):  1-1.  Abstract ( 64 )   PDF (300KB) ( 169 )   Save In view of no unified understanding of the provenance system of Jurassic Sangonghe formation in hinterland of Junggar basin, this paper comprehensively analyzed the provenance system from the gravel composition, dip logging of stratum, detrital mineral coefficient of stability, rock grain?size and the ancient landform, and suggested that the Sangonghe sediment is controlled by another Karamay, Wuerhe and Kelameily provenances. It is of great significance to guide the next step of exploration in this area Related Articles | Metrics

Application of Identification of Oil, Gas and Water Intervals to Luxi Area in Junggar Basin WU Ming1, WANG Xulong2, ZHANG Yueqian2, XIANG Baoli2, LAN Wenfang2, SUN Pingan1, CAO Jian1 2012, 33 (5):  1-1.  Abstract ( 54 )   PDF (300KB) ( 176 )   Save The distinguishing of oil, gas and water intervals is a basic task of petroleum exploration and exploitation. Geochemical methods play important roles in solving this task. In this paper, new advances of this study were shown based on a case study in Luxi area of central Junggar basin. It was found that the identification in different areas can not be settled in one rule. This is due to the geological and geochemical differences in reservoir rock. Two new geochemical indices are employed. They are organic geochemical index of grains containing oil inclusions (GOI) and inorganic geochemical index of Mn content of reservoir diagenetic calcite. From oil interval to oil?water mixed interval, to water interval, and to dry interval, these parameters have fairly good varying trend. The maximum GOI values range from >11% to 7%~11%, to 6%~7% and to <6%, and Mn content (MnO, wt%) ranges from >2.5% to 2.0%~2.5%, to 1.5%~2.0% and to <1.0%. As to the identification of gas (condensate) interval and heavy oil interval, it can be solved by biomarkers’geochemical parameters. It is shown that gas interval is characterized by the distribution of C202.0). The heavy oil reservoir is typically characterized by 25?norhopanes/html> Related Articles | Metrics

Study on Reservoir of Lei4 Member of Leikoupo Formation in Northern Sichuan Basin HU Yang1, WANG Xingzhi2, ZENG Deming2, DU Yang1, HUANG Yi2, QU Qiang3 2012, 33 (5):  1-1.  Abstract ( 78 )   PDF (300KB) ( 235 )   Save Based on macroscopic and microscopic features of outcrop sections and drilling cores of the Lei?4 member of Leikoupo formation of Middle Triassic in northern Sichuan basin, combined with the conventional petrophysical data, this paper studies in detail the basic features of the reservoir space types, lithologic and petrophysical properties, space distribution, as well as the main controlling factors. The reservoir is mainly distributed in Lei?4(3) sub?member of the Leikoupo formation, with lithology of grain dolostone, next to crystalline dolostone. The intergranular, intragranular and intercrystal dissolved pores are mainly reservoir space, cracks as the main space of percolation.The reservoir formation and evolution are mainly affected by sedimentary facies and diagenesis, among which intra?platform patch beach is the most favorable facies for developing reservoirs, and supergene karstification and burial dissolution give rise to the main storage spaces Related Articles | Metrics

Methods for Dating of Hydrocarbon Accumulation CHEN Ling1, ZHANG Wei1, SHE Zhenbing2 2012, 33 (5):  1-1.  Abstract ( 94 )   PDF (300KB) ( 276 )   Save The basic principles and methods for dating of hydrocarbon accumulation at home and abroad as well as their advantages and disadvantages are reviewed in this paper. It is suggested that the qualitative, semi?quantitative dating of hydrocarbon accumulation in the past has been developed into quantitative radiometric dating of it nowadays. By using negative thermal ionization mass spectrometry (NTIMS) and the multi?collector inductively coupled plasma mass spectrometer (MC?ICP?MS), the Re?Os isotopic dating on materials such as crude oil, bitumen and kerogen that are related to hydrocarbon accumulation can be conducted, directly making dating and giving accurate time of hydrocarbon accumulation. It is of widely prospect for application Related Articles | Metrics

Application Forward Modeling Technigue to Seismic Interpretation in Eastern Junggar Basin HUANG Yun, MEI Ling, GUAN Jian, SHI Xing, XIAO Yan 2012, 33 (5):  1-1.  Abstract ( 54 )   PDF (300KB) ( 214 )   Save By practices of lithologic targets prospecting in eastern Junggar basin, this paper highlights the key role of forward modeling technology in seismic data interpretation and processing from the following 4 aspects: (1)the quality monitoring in seismic data processing;(2)the corresponding geological meanings to the seismic reflection events; (3)the feasibility of identification for the reservoir covered by Xis?hanyao coal bed of the Jurassic; and (4)the restriction of diachroneity of the isochronic sequence interface. The results show that the effect of this method is remarkable in application in this area Related Articles | Metrics

Prediction of ReepFlat Reservoir Using High Resolution Seismic Interpretation L? Qibiao1, WU Qingjie1, BI Youyi2 2012, 33 (5):  1-1.  Abstract ( 44 )   PDF (300KB) ( 242 )   Save The reef?flat carbonate reservoir of Changxing formation in Yuanba area in northeastern Sichuan basin is characterized by average buried depth of 7 000 m, thin in thickness, serious heterogeneity and superimposed P?wave impedance between reservoir and non?reservoir intervals. So the seismic P?wave impedance inversion after poststack can not meet the needs for integration of exploration and exploitation at present. In order to get a high resolution predictable reservoir characterization and reduce the uncertainty of such a prediction andthe drilling risk, the study of prestack geostatistic inversion is carried out by fully using available seismic information. This method integrates with seismic AVO information, well logging and geological recognition, including petrophysical modeling, geological frame model and seismic data restriction, prestack geostatistic inversion. Finally, the lithologic inversion profile is obtained. The result shows high vertical and horizontal resolution and reliable lateral prediction, which allows the inversion and prediction of thin reservoirs to be effectively realized, thus improving the precision and reducing the risk of reservoir prediction Related Articles | Metrics

Formation Mechanism and Identification of Oil Bright Spot in Chepaizi Area of Junggar Basin REN Xincheng1, WANG Rui2a, WEI Xiuping2a, MA Yanjun2b 2012, 33 (5):  1-1.  Abstract ( 63 )   PDF (300KB) ( 233 )   Save High?yielding commercial oil flow was acquired from Well Pai?2 in the Neogene Shawan formation in Chepaizi area of Junggar basin. In seismic profile, since Well Pai?2 oil reservoir has bright spot characteristic, it is called“oil bright spot”. In this paper, the seismic reflection characteristic of such an“oil bright spot”was confirmed by means of forward modeling, and its formation mechanism was defined by analyzing the influence factors of wave impedance changes of the reservoir and its surrounding rocks. And then the oil bright spots were identified by using seismic amplitude attribute description, frequency decomposition and prestack AVO techniques. Three common bright spot pitfalls were also summed up by integrated with the exploration practice for the purpose of improving the success ratio of petroleum exploration in the future Related Articles | Metrics

Mapping Technology for Volcanic Overthrust Nappe Structure in Well Huo14 North Fault Block in Junggar Basin Amina1, YANG Wenhua1, Delixiati2, Paerhati1 2012, 33 (5):  1-1.  Abstract ( 62 )   PDF (300KB) ( 143 )   Save Well Huo14 north fault block is located in north side of Shazhang bruchfalten zone in Eastern uplift of Junggar basin. The target interval is the Permian Pingdiquan formation, the main part is generally beneath the carboniferous volcanic overthrust nappe. Affected by the overlying unequal thickness volcanic high?speed zone, the Permian in this block is of characteristics of fast change of lateral interval velocity, developing interference wave and poor quality of seismic data. So the complex velocity changes restrict understanding of structural features within the block and technological breakthrough in oil?gas exploration in this area. In this paper, the volcanic rock body, its distribution and contact relationship are distinguished using the forward and inversion techniques of geological model, based on which by analyzing the waveform and attribute characteristics, the volcanic overthrust nappe structural shape and highs are defined. Meanwhile, using velocity?varied mapping technique improves the structural mapping accuracy Related Articles | Metrics

Comparative Study of the Production Rate Formulas for Horizontal Wells CHEN Yuanqian1, HAO Mingqiang1, SUN Bing2, LIU Xiong3 2012, 33 (5):  1-1.  Abstract ( 77 )   PDF (300KB) ( 139 )   Save With the feature of high seepage area and low flow resistance, horizontal?well technology has been widely applied to the development of oil and gas fields in our country due to its high productivity. Meanwhile, various kinds of production rate formulas are often used to evaluate the productivity of horizontal wells. The main production rate formulas for horizontal wells which have been valued and applied in our country include: Borisov formula, Joshi formula, Giger?Resis?Jourdan formula, Renader?Dupuy formula and Chen Yuanqian formula. At present, these formulas are not used effectively because the difference and uncertainty of these formulas have not been enough mastered. In this paper, some comparisons of these formulas were studied, and some evaluation methods were also proposed, including productivity index, equivalent flow resistance, skin factor, heterogeneity and eccentricity, etc Related Articles | Metrics

The Crude Oil Property Change in Process of Development of Qigu Heavy Oil Reservoir in District No. 9(4) in Junggar Basin WANG Qun 2012, 33 (5):  1-1.  Abstract ( 66 )   PDF (300KB) ( 135 )   Save The Qigu reservoir of District No. 9(4) is characterized by high viscosity, high acid value, high colloid content, low wax, low freezing point, low sulfur, low asphaltene content and sensitive viscosity?temperature relationship. With the continuous extension of areas of the heavy oil reservoir development and the deepening of degree of development in District No. 9 (1?5), the property of in?situ crude oil has changed to a greater degree in different recovery stages. For instance, the oil viscosity, density, freezing point, colloid and asphaltene relative contents are all higher, and solution gas?oil ratio is lower. These could directly influence the percolation nature of in?situ multiphase flows, hence finally impact the recovery percent of the heavy oil reservoir in this area Related Articles | Metrics

Using GMDH Method for Analyzing Effect of ShutIn Well on Production Rate in SuperHigh Water Cut Stage WANG Luchun 2012, 33 (5):  1-1.  Abstract ( 73 )   PDF (300KB) ( 124 )   Save With the oilfield entering into super?high water cut stage and the increasing of well pattern density, the effect of shut?in well on production rate is increasing obviously, and the influencing factors become very complex. In order to predict the shut?in well on production rate accurately, this paper developed the prediction model for it by choosing the influencing factors based on synthetic dynamic analysis, using multiple correlation analysis to screen the variables and applying the group method of data handling (GMDH). The result shows that well pattern density, flow coefficient, fluid productivity intensity and water cut are the major influencing factors. The verification from actual data indicates that the model is of high predictive precision and can satisfy the field requirements. Also, it provides theoretical basis for predicting the effect of shut?in well on production rate in annual planning arrangement Related Articles | Metrics

Theoretical Methods and Application Evaluation of Water CutRecovery Percent Ratio JIANG Fengguang, WANG Xiaolin, ZHANG Xiaoning 2012, 33 (5):  1-1.  Abstract ( 53 )   PDF (300KB) ( 135 )   Save Water cut?recovery percent ratio is a new parameter for evaluating development efficiency of water flooding reservoirs. Based on Type?A and Type?C water flooding curves, the theoretical expressions for water cut?recovery percent ratio and their theoretical curves are established, respectively, and the changing feature under different water flooding laws are revealed. The case application results show that the theory corresponds to field situation, and the methods can be used to evaluate development efficiency of water flooding reservoirs Related Articles | Metrics

Prediction Methods for Incremental Oil by Chemical Flooding Process in Shengli Oil Field ZHANG Xinying 2012, 33 (5):  1-1.  Abstract ( 63 )   PDF (300KB) ( 149 )   Save The incremental oil by chemical?flooding process is the main appraisal index for the process effect and the scientific basis for its planning. This prediction method for incremental oil by chemical flooding process in Shengli oilfield is based on the analysis of incremental oil rules at all the chemical?flooding blocks in this oilfield, considering the reservoir conditions of blocks, the different development stages and methods of chemical?flooding process. For converting into water flooding projects the decline method should be used to predict the in?cremental oil; for polymer flooding projects the analog method should be used; for two?compound?combination flooding the numerical simulation method should be adopted. These prediction methods are proved to be more comprehensive and accurate for prediction of incremental oil in Shengli oil field Related Articles | Metrics

Seismic Imaging Effect of Lower Combination Complex Structures in Southern Margin of Junggar Basin Lv Huantong1, WU Yongqiang1, GAO Qi2, LUO Yong2, WANG Linhu3 2012, 33 (5):  1-1.  Abstract ( 55 )   PDF (300KB) ( 147 )   Save Related Articles | Metrics

Application of Structure Modeling and 3D Visual Technology to Junggar Basin LEI Dewen, LIU Jishan, ZHANG Yueqian, WAN Min, ZHANG Guoqing 2012, 33 (5):  1-1.  Abstract ( 46 )   PDF (300KB) ( 130 )   Save In the past, 2D mapping is the main tool for structural research that is the basis of oil exploration and development, such a graph is no intuitive or visual. 3D structural modeling and 3D visualizaion study normally focuses on local or smaller scale structures. For such a Junggar basin with developed overthrust faulting and multistage faults, it is very difficult in technology to develop basin?level 3D structural model and realize 3D visual display, undoubtedly. In this paper, the layer simulation, fault grading simulation and fault line space assignment techniques are successfully applied to Junggar basin, providing new tools for study of large?scale structutes in detail Related Articles | Metrics

Amplitude Compensation of TimeFrequency and Space Domain: Method and Application FAN Xu, TAN Jia, ZHANG Xujian, WANG Zaimin 2012, 33 (5):  1-1.  Abstract ( 67 )   PDF (300KB) ( 149 )   Save The basic principle and major steps of amplitude compensation of time?frequency and space domain are presented in this paper.The key of narrow band?pass filter frequency division is how to choose band?pass filter gate with equal band to minimize Gibbs effect and frequency leak among bands. According to the change of median of average root mean square amplitude in each time gate of model shot gathers from shallow to deep, linear equations of ground absorption and attenuation coefficients are derived to get unified amplitude com?pensation coefficient for each frequency band in whole area by using least square method. Except previous compensation, space domain compensation is conducted by counting amplitude attenuation curves of shots in whole area for near?surface explosion effect in different frequency bands. Real data processing effects show that amplitude compensation in time?frequency and space domain is much better in quality than common spherical diffusion and absorption compensation method Related Articles | Metrics

Application of Fractal Geometry Method to Prediction of Fractures in Kela2 Gas Field of Tarim Basin ZHAO Libin1, DAI Junsheng2, SUN Yong1, FENG Zhendong2, XIAO Xiangjiao1, LI Chongyue1, ZHANG Jie1 2012, 33 (5):  1-1.  Abstract ( 54 )   PDF (300KB) ( 144 )   Save Based on the accurate recognition of fractures in well point of Kela?2 gas field, this paper established the relationship between the fractal dimension of fault and the fracture density, and predicted the fracture distribution between wells by the fractal dimension of fault. The study results indicate that (1) the fractures in this area are dominated by structural fracture, with most half?filled and high?angle ones, and the fracture aperture ranges fror 0.1 mm to 0.4 mm, and linear density from 0.142 n/m to 1.842 n/m; (2) the fractal dimension of fault in well point can be used to predict the degree of fracture development, for it is of positive correlation with linear density of fracture interpreted from well logging data; (3) the area with fractal dimension value bigger than 1.2 is favorable to the generation of fractures, and in area with that bigger than 1.25, fracture is most developed Related Articles | Metrics

Application of Volumetrictric Attributes Analysis to Fine Structural Interpretation ZHANG Xufeng1,2, ZHANG Jinxue2, MOU Kexun2, XU Tao2 2012, 33 (5):  1-1.  Abstract ( 53 )   PDF (300KB) ( 145 )   Save It is one of the main factors in figuring out the complicated fault system and increasing the precision of structural interpretation to efficiently suppress seismic background noise and improve seismic data resolution. It is found that the S/N ratio and faults and lithological boundaries are much higher and clearer after using structural?oriented filtering in processing seismic data, and the fault interpretation precision is greatly improved through C3 coherence cube, curvature, and other attributes analyses and interpretations, which is helpful to characterization of the faults distribution and structural feature Related Articles | Metrics

Application of Volumetrictric Attributes Analysis to Fine Structural Interpretation ZHANG Xufeng1,2, ZHANG Jinxue2, MOU Kexun2, XU Tao2 2012, 33 (5):  1-1.  Abstract ( 30 )   PDF (300KB) ( 135 )   Save It is one of the main factors in figuring out the complicated fault system and increasing the precision of structural interpretation to efficiently suppress seismic background noise and improve seismic data resolution. It is found that the S/N ratio and faults and lithological boundaries are much higher and clearer after using structural?oriented filtering in processing seismic data, and the fault interpretation precision is greatly improved through C3 coherence cube, curvature, and other attributes analyses and interpretations, which is helpful to characterization of the faults distribution and structural feature Related Articles | Metrics

Application of Volumetrictric Attributes Analysis to Fine Structural Interpretation ZHANG Xufeng1,2, ZHANG Jinxue2, MOU Kexun2, XU Tao2 2012, 33 (5):  1-1.  Abstract ( 45 )   PDF (300KB) ( 146 )   Save It is one of the main factors in figuring out the complicated fault system and increasing the precision of structural interpretation to efficiently suppress seismic background noise and improve seismic data resolution. It is found that the S/N ratio and faults and lithological boundaries are much higher and clearer after using structural?oriented filtering in processing seismic data, and the fault interpretation precision is greatly improved through C3 coherence cube, curvature, and other attributes analyses and interpretations, which is helpful to characterization of the faults distribution and structural feature Related Articles | Metrics

Distribution of Tricyclic Terpane and Sterane with Application to OilSource Correlation in Southern Turgay Basin CHEN Anding1, ZHAO Junfeng2, QI Jianhua3, SHAO Manjun3 2012, 33 (5):  1-1.  Abstract ( 44 )   PDF (300KB) ( 123 )   Save The source rocks of Aryskum depression in southern Turgay basin are mainly in Middle?Lower Jurassic, which contain three types of kerogen, i.e. humic?sapropelic, sapropelic?humic and humic ones, being at low mature?mature and locally high mature stages. Aryskum depression has a structure in alternative arrangement of sags and swells, in which oil and gas generally occur in sags with multiple sets of sources rocks and store in swells. So the oil sources is difficultly distinguished by the difference and similarity of sedimentary environment and kerogen properties between the sags and the strata. According to the data analysis, sterane in the crude oil is divided into four distribution types of Ⅱ1, Ⅱ21, Ⅱ22, III and tricyclic terpane into two series with 11 distribution types. Using "the unknown peak" of tricyclic terpane to distinguish source rocks in different sags and using distribution assembly of sterane?tricyclic terpene to find out specific position of the source rocks, by which the oil?source distinguishing problem is successfully solved Related Articles | Metrics

Application of Horizontal Well Selected Interval Steam Injection to Super Heavy Oil Development SUN Zhenbiao 2012, 33 (5):  1-1.  Abstract ( 71 )   PDF (300KB) ( 142 )   Save With the continuous expansion of super heavy oil development by horizontal well steam injection process in District Shu?1 of Liaohe oilfield, the uneven production by horizontal well interval highlights the unfavorable influences on its efficient development. It is determined that the technique of steam allocation for selected intervals should be adopted on the basis of the temperature monitoring data for reasonable judgment of producing level of the horizontal well intervals. Therefore, the horizontal intervals can be divided into several separate steam injection chambers in order to make a flexible adjustment of steam injection rate，achieve the uniform steam injection，adjust the horizontal steam injection section, improve the producing degree，and finally improve the development effect. This technique provides the technical support for sustainable and stable production of super heavy oil development in this area Related Articles | Metrics

The Reason Analysis for Surface Steam Breakthrough in Super Heavy Oil Reservoir ZHANG Jing, LANG Jianjun, XIE Shouchang, WANG Guojun, JI Yongjun 2012, 33 (5):  1-1.  Abstract ( 63 )   PDF (300KB) ( 139 )   Save The steam stimulation exploitation of super heavy oil is of obvious characteristic of interlayer steam breakthrough, resulting inloss of productivity and not producing of the reserves in area with steam breakthrough. Because the steam injection pressure is much higher than the reservoir pressure, a number of cracks may produce between casing and cement sheath after a period of production by steam stimulation process. Follow?up injected steam will flow up along the cracks and enter into overlying sand layer from the weak parts of cement sheath. When the steam amount reaches a certain degree and steam injection continues, the steam will erupt from the weak parts of the sand layer and form steam breakthrough. The reason for this is that the production?steam injection ratio is less than 1 and long?term steam injection in high pressure during steam stimulation development of the super heavy oil in this area. It is suggested that to increase the drainage capacity and plug the cracks in casing are the feasible solutions Related Articles | Metrics

The Strategic Thinking of Realizing Sustainable Development in Xinjiang Oilfield WANG Congle, LI Weijuna, WU Xuquanb, YUAN Wentaob, CHEN Pengb 2012, 33 (5):  1-1.  Abstract ( 91 )   PDF (300KB) ( 139 )   Save The development current situation and the influence factors of sustainable development of Xinjiang oilfield is analyzed, and the development capacity and development trend are predicted. It is suggested that Xinjiang oilfield’s conventional oil?gas exploration and development at present is in the early?middle stages, while non?conventional oil?gas resources exploration and development is at the early stage, so the resources used for its sustainable development are abundant. Based on this, the overall thinking and four development strategies in this oilfield are presented, and the six effective paths for realizing the sustainable development are proposed in this paper Related Articles | Metrics

Natural Gas Reserves Growth Prediction and Exploration Potential Analysis in Junggar Basin WANG Yutao, LUO Jianling, GAO Qi, XIANG Ying, LEI Ling 2012, 33 (5):  1-1.  Abstract ( 96 )   PDF (300KB) ( 171 )   Save Based on Weng’s cycle theory, a life?cycle prediction is performed with HCZ model for the growth trend of natural gas reserves in Junggar basin. The result shows that the peak of proven reserves will occur in the year of 2027 with the annual proven reserves of 268.49×l08 m3 and the corresponding proven ratio of 25.8%. Till the year of 2092, the cumulative proven reserves will be 1.42×l012 m3 and the cumulative proven ratio of resources will reach 67.52%. A series of analyses are conducted on natural gas resources and its exploration status and potential in Junggar basin. It is considered that the natural gas exploration of Junggar basin is still in its early stage and giant potential of resources remains to be explored; there are two directions and targets for petroleum exploration: the first one is to stick to looking for coal?formed gas around the areas with abundant humic parent materials such as the lower combination in southern margin of Junggar basin (the Middle?Lower Jurassic coal?formed gas), volcanic reservoirs in the hinterland (the Carboniferous coal?formed gas) and Zhongguai in the northwestern margin?District 5?8 (the Lower Permian Jiamuhe coal?formed gas); the second one is to conduct study on over?mature cracked?gas in the center of the basin so as to make a breakthrough as soon as possible Related Articles | Metrics

Discussion About Rock Compressibility and Porosity Applied in Oilfield Development DOU Hongen 2012, 33 (5):  1-1.  Abstract ( 75 )   PDF (300KB) ( 127 )   Save This paper analyzed the misconceptions published in some literatures in recent years that there is no stress sensitivity, porosity is invariable and no threshold pressure in low permeability reservoir during oil field development, and points out the causes of these misconceptions: one is incorrect hypotheses, the other is optional substitution for conceptions. By tracing the sources of a number of basic formulae in rock mechanics, which are the original or fontal researches, some issues about the rock porosity and rock compressibility in field application are discussed. It is suggested that to prevent the mistakes in scientific researches and make some innovations depends only on inheritance and development of previous research results, which is the real starting point of scientific research, while distorting the scientific concepts and blindly denying previous achievements should be inhibited in scientific researches Related Articles | Metrics

Approach to Sealing Ability of Biological Gas Cap Rock of Quaternary in Eastern Qaidam Basin CAO Qian1, JIN Qiang2, CHENG Fuqi3 2012, 33 (5):  1-1.  Abstract ( 63 )   PDF (300KB) ( 139 )   Save The gas reservoir of the Quaternary in eastern Qaidam basin is characterized by unconsolidated and un?diagenetic cap rocks with high porosity and permeability. It has unique sealing mechanism and model for formation of large?scale gas reservoir. This paper calculates the displacement pressure difference between cap rock and reservoir，the theoretical sealed gas?column height, and then evaluates the sealing efficiency, obtains the time that biogas broke through the cap rock and the gas seepage flow rate, and reveals the sealing process of the gas reservoir. The results show that the effectiveness of the un?diagenetic cap rock is becoming better with increase of buried depth, and when real gas reservoir’s gas?column height is bigger than the theoretical sealing gas?column height, the gas below it can percolate and be lost through the cap rock. However, the flow process is short, and then the gas reservoir is also in sealing condition. It is concluded that it is dynamic balancing process for the sealing and seepage of gas reservoir, so the stacked reservoir and cap rock can still seal a certain amount of gas by displacement pressure difference. This could be the stacked sealing model for un?diagenetic gas cap rocks Related Articles | Metrics

Geochemical Characteristics of Source Rocks in Central Sag of Bongor Basin, Chad SONG Huanxin, WEN Zhigang, ZENG Yantao 2012, 33 (5):  1-1.  Abstract ( 79 )   PDF (300KB) ( 201 )   Save The comprehensive research of the source rocks of the Lower Cretaceous in central sag of Bongor basin in Chad was conducted in this paper, based on the organic geochemical analysis data of the source rocks, from the aspects of source rock evaluation, history of the hydrocarbon generation and characteristics of the biomarkers, etc. The result indicates that the studied area is of characteristics of developed dark mudstone, high abundance of organic matter, good source rocks, Ⅱ1 organic matter type, effective source rocks dominated by K formation and its below M and P formations, and maturity as the key controlling factor of effective source rocks. The result of the history simulation of hydrocarbon generation indicates that the source rocks of K, M and P formations even reach the peak stage of hydrocarbon generation in or earlier than the Late Cretaceous and have large potential of resources, and the secondary hydrocarbon generation is impossible. The biomarkers analysis shows that the source rock of K formation deposits in fresh water?weak salt water and weak oxidation?weak reduction lacustrine sedimentary environment, but there are some differences in different layers and structural locations Related Articles | Metrics