Table of Content

01 January 2019, Volume 37 Issue 2 Previous Issue    Next Issue

For Selected:

Download Citations EndNote Reference Manager ProCite BibTeX RefWorks

Toggle Thumbnails

Formation and Evolution of Jiange PaleoUplift in Northwestern Sichuan Basin and Gas Controlled Effect WANG Nai1,2, WEI Guoqi2, YANG Wei2, WANG Yuwei3 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160201 Abstract ( 105 )   PDF (300KB) ( 162 )   Save Paleo?uplifts are the major areas for petroleum exploration in Sichuan basin. Research on the structural configuration, formation and evolution as well as gas?controlled effect has great significance for petroluem exploration in northwestern Sichuan basin. This paper studied the distribution and evolution process of Jiange paleo?uplift using the geologic, geophysical and well logging data, combined with the sedimentary thickness of the Upper Triassic Xujiahe formation in northwestern Sichuan basin. The result shows that the paleo?uplifting process can be divided into three stages: the embryo stage (T3x1-T3x3), the mature stage (T3x4-T3x6), and the destruction stage (J1z). The Jiange paleo?uplift is of complete evolution cycle, the Xujiahe formation is of good soruce?reservoir?caprock assemblage, and the multistage tectonization?formed stratigraphic and lithologic traps are the favorable targets for petroleum exploration in northwestern Sichuan basin Related Articles | Metrics

Optimization of Favorable ReservoirCaprock Assemblages of MiddleUpper Permian in Mahu Sag, Junggar Basin YANG Fan1, WEI Yanzhao1, Abulimiti2, CHEN Gangqiang2, BIAN Baoli2 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160202 Abstract ( 58 )   PDF (300KB) ( 58 )   Save This paper presents the sequence stratigraphic classification of single well of the Middle?Upper Permian in slope area surrounding Mahu sag of Junggar basin, and the sequence stratigraphic correlation of well logging and seismic profile, dividing the Xizijie formation,the Lower Wuerhe formation and the Upper Wuerhe formation into two second?order sequences and six third?order sequences, and recognizes the thick glutenite reservoirs of the middle?lower part of Xizijie formation, the lower and upper parts of Lower Wuerhe formation, and Upper Wuerhe formation, as well as three regional caprocks in the upper part of Xizijie formation, the middle part of Lower Wuerhe formation and the top of Upper Wuerhe formation, by which three favorable reservoir?caprock assemblages are given. The middle and lower assemblages are controlled by low stand system tract’s slope break belt, and dominated by lithologic and structural?lithologic reservoirs; the upper one is controlled by large?scale unconformities of the Permian-Triassic and the Lower Wuerhe formation-Upper Wuerhe formation,dominated by stratigraphic reservoir, and characterized by relatively shallow burial, matching well with oil source faults and high efficient petroleum transport system, it could be an important area for the recent hydrocarbon exploration Related Articles | Metrics

Geochemical Characteristics of Aromatic Hydrocarbons in Crude Oil of Shawan Formation in Chunguang Block, Northwestern Margin of Junggar Basin YIN Qina,b, YAN Yongxina, WANG Yonga, JIA Xiuronga, JI Tiantiana, MA Rongfanga 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160203 Abstract ( 73 )   PDF (300KB) ( 184 )   Save In order to ascertain the oil?gas origin in Chepaizi area in northwestern margin of Junggar basin, this paper studied the 40 crude oil samples from the Miocene Shawan formation in Chunguang block of this basin using GC?MS analysis, and presented the distributions and compositions of aromatic hydrocarbons biomarker, as well as their geological and geochemical implications. There are abundant aromatic hydrocarbons detected in Shawan crude oil, which can be regarded as important basis for judgement of the organic matter maturity, kerogen type, hydrocarbon charge and migration direction. The study shows that the Shawan crude oil is in mature stage, formed in continental oil environment, and its kerogen contains a certain extent of imput higher plants, and there exist some defferences among them for different types of crude oils. According to the ratio index and m(4?MDBT)/m(1?MDBT), the Shawan crude oil in this area is originated from WS to ES directions, and characterized by that the light crude is close to hydrocarbon source area, with single oil source; the intermediate and heavyoils are relatively far from it, the former is mixed oil, the latter is highly degraded one Related Articles | Metrics

Model for StrikeSlip Fault Zones and Karst Reservoir Development of Ordovician in Northern Slope of Tazhong Uplift, Tarim Basin HAN Jun1, CAO Zicheng1, QIU Huabiao1, YOU Donghua2, ZHANG Zhongpei3 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160204 Abstract ( 74 )   PDF (300KB) ( 104 )   Save Several NE-SW strike?slip fault zones are distributed in the Ordovician strata in northern slope in Tazhong uplift of Tarim basin,along which a lot of oil and gas seepages were discovered in carbonate rocks of the Ordovician from many drilled wells. Study on the inside carbonate reservoir feature and origin, as well as the relationship with the strike?slip fault zones is one of key issues for petroluem exploration in it. This paper presents comprehensive analysis of the development features, lithologic and geochemical data from 4 typical wells (i.e.A, B, C, and D wells) drilled in the Ordovician reservoir. And combined with the regional geologic setting and igneous rock characterisitcs,it considers that such a reservoir development may be related to plutonic karst fluid transformation with different properties, among which Well A may be related with the regional igneous intrusions?relevant fluid, while Wells B, C, D could be related to the deep hydrothermal fluids in silicon formations. Based on these, the segmentation and deformation intensity of 3 strike?slip fault zones are analyzed semi?quantitatively. Compared with the actual drilling situations, it is concluded that the segmentation of strike?slip fault zones may control the position of the reservoirs, where transtension part is better than pressure torsion part; whereas transformation intensity may control the scale of it,and the greater the intensity, the bigger the scale is. Finally, this paper develops the model for such fault zones and plutonic karst reservoirs in this area, so as to provide a new idea for petroleum exploration and evaluation of this inside carbonate reservoir Related Articles | Metrics

Rock Mechanics Characteristics of Lucaogou Tight Oil Reservoir in Jimusaer Sag, Junggar Basin GAO Yang1, WANG Yingwei1, WANG Yuduo2, XIE Tianshou1, LIU Gang3, WANG Li1 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160206 Abstract ( 83 )   PDF (300KB) ( 168 )   Save Tight oil reservoir in Jimusaer sag of Junggar basin is characterized by huge reserves, poor porosity and permeability, low singlewell production, long production cycle, and high development cost. Systematic study of its petrophysical mechanics and ground stress characteristics have become the key of the tight oil reservoir exploration and development. For this reason, this paper developed the logging evaluation model of the petrophysical mechanics parameters, optimized the measures of engineering technology, selected whole diameter cores of Ji?A and Ji?B wells, and conducted acoustic wave and triaxial compression experiments under three confining pressures of 0.689 5 MPa, 11.032 0 MPa and 22.064 0 MPa. The results show that there exists obvious correlation between longitudinal?shear wave velocity and dynamic?static Young’s modulus; the triaxial compression strength is linearly increasing with the confining pressure increase, and the confinning pressure has a significant effect on compressive failure of specimen Related Articles | Metrics

Prediction of Inner Dolomite Reservoir Distribution of Ordovician in Eastern Segment of Maigaiti Slope, Tarim Basin TIAN Lei1, CUI Haifeng1, ZHANG Nianchun1, FENG Xiaojun2, ZHANG Jijuan1 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160205 Abstract ( 44 )   PDF (300KB) ( 112 )   Save Based on the drilling, seismic data, this paper analyzed the reservoir characteristic and its seismic response characterisitc in order to find out the inner dolomite reservoir distribution in eastern Maigaiti slope in Taxinan depression of Tarim basin. The result shows that fractured?vugging reservoirs are widely developed in the inner dolomite in this area, with beads?like strong amplitude anomalies on the seismic profile, and controlled by faults and fractures formed from tectonism. The seismic prediction result indicates that the inner dolomite reservoirs are widely stellate distributed in the south slope of Mazatag structural zone in eastern Maigaiti slope. There are good comparability among such dolomites and Tazhong and Gucheng areas in terms of developed horizon, reservoir type, reservoir?cap rock assembly and seismic response, etc, which could be regarded as a breakthrough target for oil and gas discovery in Maigaiti slope area Related Articles | Metrics

Abnormal High Pressure and Tight Oil Enrichment of Lucaogou Formation in Jimusaer Sag LIAN Huan1, ZHA Ming1, GAO Changhai1, TANG Yong2, DING Xiujian1, QU Jiangxiu1 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160207 Abstract ( 73 )   PDF (300KB) ( 279 )   Save The tight oil reservoir of the Middle Permian Lucaogou formation in Jimusaer sag is of good hydrocarbon potential. Its enrichment mechanism is greatly different from that of conventional oil?gas reservoirs. This paper calculated the fluid pressure of this formation,established the abnormal high pressure distribution system of it, and combined with the geologic conditions, geochemical analysis and formation testing of key wells, it discussed the relationship between the abnormal high pressure and tight oil enrichment. The results show that the Lucaogou reservoir is of typical source?reservoir structure, and the tight oil generated from high?quality source rocks in low mature?mature stage is characteristic with both source and reservoir within the source rocks, and migrates in short distance between source rocks,which is the main reason for forming the abnormal high pressure. Such abnormal high pressure is widespread in the source rocks and the reservoirs, with lateral stability and connectivity, showing a certain stratabound characteristic; with longitudinal differences in organic matter abundance and hydrocarbon?generated ability in different strata, resulting in uneven distribution of the abnormal high pressure, indicating that there exists distinct remained fluid pressure of interlayers. Such a remained fluid pressure could be the main force for the tight oil vertical migration, and the distribution belt of big difference of the remained fluid pressure of interlayers might be the favorable area for tigh oil enrichment Related Articles | Metrics

Cycle Division Based on Matlab Wavelet Analysis and Its Geologic Implication: A Case Study of Pinghu Formation in Pb1 Well of Pingbei Section in Baojiao Slope Belt of Xihu Sag, Donghai Basin XIE Guogen1, ZHENG Jun2 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160208 Abstract ( 58 )   PDF (300KB) ( 226 )   Save Taking the Pinghu formation of Eocene in Well Pb?1 of Pingbei section in Baojiao slope belt in Xihu sag of Donghai basin as an example, the geologic information contained in GR logging data from Well Pb?1 Pinghu formation are analyzed using Matlab wavelet. Based on the time?frequency energy and curve characteristics of the wavelet transform coefficient after transforming, the coal?bearing strata of the Pinghu formation are divided into 3 long?term cycles and 5 middle?term cycles, which show that the wavelet transform has higher resolution in well logging sequence stratigraphic division, by which the characteristics of hidden sedimentary cycles can be recognized. On the basis of these, this paper discussed the relationship between the curves of wavelet transform coeficients in different scales and the coal measures positions. The result indicates that the coal measures in the study area are mainly located in the positions with relatively small peak value on the curves, which correspond to the delta retrograding process within the long?term cycles and the delta retrograding?prograding conversion period within the middle cycles Related Articles | Metrics

Quantitative Description and Evaluation of Vuggy Carbonate Reservoir of Yingshan Formation in Tazhong Area, Tarim Basin WANG Jingyi1, TAN Fei2, ZHAO Yiru2, JIANG Ning2, ZHANG Zhenghong3, ZHANG Min3 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160209 Abstract ( 61 )   PDF (300KB) ( 124 )   Save Vuggy reservoir is one of important types of carbonate reservoirs, its complex and varied features in horizon, scale, filling matter type and filling degree, etc, make the reservoir difficult to be quantitatively discribed using single geophysical model or well logging model.This paper determines the depth of the vuggy carbonate reservoir of Yingshan formation in Tazhong area with the seismic attributes, discribes the vertical scale of vugs, filling matter property and filling degree by imaging logging?conventional logging combination, and evaluates the lateral distribution of vugs by means of the well testing, production test data and the interwell seismic attributes. The studies show that the vuggy carbonate reservoir in this area is characterized and dominated by moniliform seismic reflection, which accounts for 86%,with distribution range of 240 m away from the top Yingshan formation, and the vugs or caves mostly range from 0.5 m to 2 m in height, semifilled and/or fully filled with clay, breccia, etc, with filling rate of 62.8% in average. In lateral, the distribution of vugs is isolated, partly forming fractured?vuggy reservoir with fractures Related Articles | Metrics

SubLayer Correlation Method and Application Based on Braided River Outcrop Geometric Model: A Case Study of Enping Formation in Oilfield A, Pearl River Mouth Basin JU Zilong1, TANG Hui1, LIU Weixin1, DAI Zong1, CHEN Cheng2, LI Qingmin1 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160210 Abstract ( 66 )   PDF (300KB) ( 178 )   Save From the braided river outcrops of Houcheng formation of Middle Jurassic at Junzhuang town, Mentougou region in Beijing, it is observed the cross?section of the braided river distributary channel is characterized by gradual thinning of thickness from channel center to channel wings. Considering the channel changing system, this paper presents the geometric model of the cross?section is that besides the thinning feature, it appears the unsymmetric semi?ellipse with flat top and swell bottom. Using the geometric model and the conventional “sand to sand and shale to shale”sub?layer correlation methods, the correlation of single sand body sublayer of the Enping formation in oilfield?A braided river sedimentary system in Pearl River Mouth basin is conducted. The result shows that the geometric model?based sublayer correlation method can be applied to explain the lateral difference between sand body number and sand thickness of interwells and longitudinal evolution pattern of the sedimentary center through the spatial distribution characteristics of braided river channels, and is more applicable in study of complicated sedimentary system like braided river, compared with conventional sub?layer correlation method Related Articles | Metrics

Evaluation and Improvement of Relationship Between Cumulative Water Preservation Rate and Recovery Degree GAO Wenjun, FU Chunmiao, CHEN Shuyan, SONG Chengyuan, HUANG Ying 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160211 Abstract ( 142 )   PDF (300KB) ( 287 )   Save The law of water cut and recovery degreein most of the domestic waterfood oilfield conforms to the S?type curve. This paper derives the relationship between the cumulative water preservation rate and the recovery degree of the S?type curve and presents the method for getting parameters to be determined, based on the S?type curve integrated with material balance equation, thus realizing the conversion of recovery vs. water cut into cumulative water preservation rate vs. recovery degree in theory. The study indicates that regarding the waterflood recovery of the relationship between cumulative water preservation rate and recovery degree as a variate, the chart of cumulative water preservation rate vs. recovery degree in varied waterflood recovery of an oilfield can be drew out, by which evaluation of oilfield waterflood efficiency can be more effective, and the waterflood status can be well revealed or understood. Finally, taking Shanshan oilfield and Qiuling oilfield as example, this paper proposes the suggestions for improving the waterflood effects of them Related Articles | Metrics

Comprehensive Clustering Evaluation of FracturedVuggy Carbonate Reservoirs by Depletion Drive Process WANG Daigang1,2, LI Yong1, HU Yongle1, LI Baozhu1, ZHANG Lijuan3, CHEN Fangfang3 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160212 Abstract ( 68 )   PDF (300KB) ( 109 )   Save Fractured?vuggy carbonate reservoir is characterized by varied models of reservoir development, complex storage spaces, serious heterogeneity, and great development difficulties. This paper presents comprehensive clustering evalation of its depletion drive characteristics, through modified fuzzy C?means (FCM) analysis, develops a new approach for comprehensive evaluation of such a reservoir by depletion drive process. Based on the well production performance data, it introduces the discrete particle swarm optimization algorithm to overcome the inherent limitations of conventional FCM clustering analysis that depends on the arbitrary setting the number of clusters and the initial clustering center, and easily getting stuck in local optimal solution. Using this approach, a total of 62 key oil wells in M fracturedvuggy carbonate reservoir are classified and evaluated comprehensively into four categories and eight subclasses, providing the classification standard of dynamic attributes of all kinds of oil wells. The case study indicates the reliability of this approach for differentiation comprehensive treatment and preparation of EOR countermeasures Related Articles | Metrics

Calculation of Pressure Factor and Spontaneous Production Factor under Special Conditions LI Chuanliang, ZHU Suyang 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160223 Abstract ( 157 )   PDF (300KB) ( 292 )   Save Pressure factor is a basic parameter for petroleum reservoir evaluation, which can be used to analyze the pressure status of reservoirs. However, in an area or reservoir with uneven surface and/or high hydrocarbon column, the calculation of pressure factor may lead to result with large deviations. This paper studies the reasons for the phenomena above. For the area with uneven surface, it is the calculation of hydrostatic pressure that leads to the deviations, which can be eliminated by replacing the depth from surface with depth from water level. For the reservoir with high hydrocarbon column, it is the mischoice of calculation datum depth of pressure factor that results in deviated pressure factors, which can be eliminated by using the middle depth rather than the top or bottom depth of hydrocarbon column. The intercept pressure of hydrostatic pressure-depth curve, a surplus pressure of reservoir fluids flowing from underground to surface, is defined as spontaneous production factor of reservoir fluids. The larger the spontaneous production factor, the stronger the ability of reservoir fluids to flow spontaneously Related Articles | Metrics

Prediction of Overpressures Generated by Fluid Expansion: Methods and Application JING Chen1, LIU Hua1, JING Xiao2, FENG Yuelin1, ZHAO Meng1 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160222 Abstract ( 79 )   PDF (300KB) ( 193 )   Save Accurate pore?pressure prediction in overpressured regions is essential to ensure safe drilling operations，also provides essential data for reservoir planning and reserves estimation. Based on the differences of petrophysical signatures between different overpressure mechanisms，the prediction method for overpressure generated by fluid expansion mechanisms was syudied. The results showed that the Eaton method is suitable for estimating overpressure generated by different mechanisms. Taking Bonan sag of Zhanhua depression in the Jiyang subbasin as an example，the procedure of determining the exponent c and predicting fluid pressure by Eaton method were explained.At first，it is initially identified that the exponent c was between 1 to 4. Then，introducing a parameter the sum of the squares of relative error and using the iterative method，the exponent c could be determined by comparing the different sum of the squares of relative error. The results showed that the sum of the squares of relative error was the smallest when the Eaton exponent is 2.6，and the prediction was most accurate Related Articles | Metrics

A New Method for Calculating Ratio of Vapor to Liquid Phase Volume of Oil Inclusions DENG Mo 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160221 Abstract ( 72 )   PDF (300KB) ( 118 )   Save Paleopressure can be obtained by oil inclusion thermodynamics modeling, and ratio of vapor to liquid phase volume of oil inclusion is a sensitive parameter in this modeling, which can be got by 2D plane analysis and 3D shape reconfiguration of petroleum inclusions.The case study shows that within a certain oil conclusions shape, this ratio obtained by 2D plane analysis and 3D shape reconfiguration has relative error within ±10%, compared with the ratio given by confocal laser scanning?fluorescence scanning microscopy (CLFSM). WithoutCLFSM, the 2D plane analysis and 3D shape reconfiguration method is better than ocular estimation measurement method in calculation of the ratio, and can meet the accurate requirement for trapping pressure modeling of petroleum inclusions Related Articles | Metrics

A Comprehensive Prediction Model Based on Usher Model and Water Drive Characteristic Curves CHEN Guofei1, SUN Aiyin1, TANG Hai1, L?Dongliang1, LIANG Yi2 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160220 Abstract ( 85 )   PDF (300KB) ( 208 )   Save Combined Usher model with water drive curves , this paper presents a new simultaneous solution model for predicting water cut,oil production rate, water production rate, fluid production rate and cumulative oil production variations with development time and recoverable reserves of a water drive oilfield. This model solves the problems without water cut parameter in yield prediction model and without time factor t in water drive curves. Case study shows that the prediction accuracy by this model is relatively higher than others and the model can satisfy the requirements of performance prediction of development indices in water drive oilfields Related Articles | Metrics

Application of CT Scanning System to Study of MicroPore Structure of Tight Sandstone: A Case Study of Chang7 Member of Yanchang Formation in Ordos Basin YOU Yuan1,2a, NIU Xiaobing1,2a, LI Tingyan1,2a, YANG Xiao2b, DAN Weidong1,2a 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160219 Abstract ( 74 )   PDF (300KB) ( 348 )   Save In order to reveal the complicated pore structure characterisitcs of tight sandstone, this paper made a quantitative study of the tight sandstone sample from the Chang?7 member of Yanchang formation in Ordos basin by high?resolution CT scanning system, obtained the high?accuracy 2D and 3D pore throad images of it by using CT threshold differences, developed the tigh sandstone pore network model using digital core method, and conducted quantitative parameter statistics and analysis from this model, obtaining the radius distribution of pores and throats and their contributions and pore throat connectivity characterisitcs to the tight sandstone storage spaces, hence realizing the quantitative characterization of micro?pore structures of the tight sandstone. The results show that the tight sandstone of Chang?7 member of Yanchang formation in Ordos basin is characterized by continued distribution of micron pore throats, different contributions of different radius pores to the storage spaces, of which the pores with radius over 2 μm are the main storage spaces of it, and a certain connectivity between pores and throats, with coordination number from 1 to 3 Related Articles | Metrics

Quantitative Prediction of Coalbed Gas Content: Technique and Application SHAO Linhai1,2, XU Ligui2, LI Xingtao3, ZHANG Lei2, HUO Lina2, DING Qingxiang2 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160218 Abstract ( 58 )   PDF (300KB) ( 135 )   Save Coalbed gas content is one of important parameters for coalbed methane (CBM) resource estimation, favorable area evaluation and well deployment. It is related to many factors and difficult to predict. This paper focuses on Baode south survey in the north of the eastern Ordos basin. According to the cross plot of logging data and real gas content of coal core, the density of coal bed is the most relevant factor of gas content, and the relationship between them is derived. Combined with the research of 3D seismic data, the density data and the coal density attribute are obtained by pre?stack simultaneous inversion, and then the lateral distribution of coalbed gas content is predicted quantitatively. The technique applied in the Baode south survey in the north of the eastern Ordos basin for quantitative coalbed gas content prediction can support the research of the coalbed gas content for the favorable area evaluation and the well deployment Related Articles | Metrics

Method for Fracturing Stage and Cluster Optimization in Shale Gas Horizontal Well WANG Haitao1, JIANG Tingxue1, LI Yuanzhao2, BIAN Xiaobing1, HUA Jijun2 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160217 Abstract ( 73 )   PDF (300KB) ( 145 )   Save To further improve the effectiveness of staged fracturing design for shale gas horizontal well, a comprehensive fracturing stage and cluster optimization method was studied. Based on the results of numerical simulation and fracturing simulation, considering the effect of actual fracture geometry and multi?fracture parameters, this paper presents an orthogonal design method for sectional parameters optimization; after that, it proposes a W?type staged fracturing model for obtaining maximum productivity; according to multiple cluster?fracture stress interference and induced stress distribution, it establishes a more reasonable clustering optimization method; considering the geologic attributes and engineering features in real trajectory of shale gas horizontal well, it provides a comprehensive optimization method of fracturing stage and cluster in terms of geologic long segment and engineering short segment Related Articles | Metrics

Hydraulic Fracture Monitoring and Physical Simulation Experiment for UShaped Horizontal Well with Coalbed Methane (CBM) in Jixian Block XIU Nailing1,2, YAN Yuzhong1,2, FU Haifeng1,2, DOU Jingjing1,2, HUANG Gaochuan1,2, LIANG Tiancheng1,2, LUO Yu2 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160216 Abstract ( 47 )   PDF (300KB) ( 83 )   Save Accurate understanding of the hydraulic fracture morphology and orientation can be of significance for horizontal well deployment and fracturing design optimization. Nine sections of hydraulic fractures are monitored using tiltmeter, and the morphologies of them are obtained, followed by physical simulating in?situ stress state in this block and hydraulic fractures in CBM using true triaxial hydraulic fracturing simulation system. Monitoring and the experimental results show that the fracture propagation is dominated by horizontal fracture. To make hydraulic fracturing within one of the layers by horizontal well process is hard to shape effective connection of the multiple layers in longitudinal direction. It is concluded that such a process of horizontal well plus hydraulic fracturing to connect multiple layers in Jixian block has a great risk of investment Related Articles | Metrics

Productivity Prediction of Fracturing Well with Complex Hydraulic Fracture Network in Tight Oil Reservoir PU Xieyanga, HU Yongquana, ZHAO Jinzhoub 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160215 Abstract ( 58 )   PDF (300KB) ( 152 )   Save The nonlinear fracture extension in tight oil reservoir by hydraulic fracturing is characterized by statistic self-similarity, and the complex hydraulic fracture system can be described by the fractal bifurcate tree network theory. Based on fluid diffusion theory and pressure drop superposition principle, this paper uses semi?analytical method to estiblish the corresponding mathematic models for reservoir seepage and fracture seepage, and predicts the unstable productivity of a fracturing well through iterative algorithm, including influencing factors analysis of the productivity. The results show that the smaller the matrix permeability, the greater the contribution ratio of production rate from branch fractures, and the more favorable for generating complex fracture network. During the early production, the production rate from branch fractures is lower; up to quasi?steady state period, the production rate from branch fractures is increased rapidly, and the stable production stage is prolonged. The more complex the hydraulic fracture system, the larger the effective contact area of hydraulic fractures and the higher the production rate; also, the higher the branch fractures flow conductivity, the higher the production rate is. So, additional complex hydraulic fracture networks and incremental branch fractures flow conductivity are favorable for high and stable production of a fracturing well in tight oil reservoir Related Articles | Metrics

Evaluation of DST Deliverability in Narrow Channel Sand Reservoir in BZ251s Oilfield, Bohai Sea HE Yifan, HU Yong, ZHOU Haiyan, WANG Quanlin, XIE Lisha 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160214 Abstract ( 50 )   PDF (300KB) ( 199 )   Save BZ25?1s oilfield is a narrow channel sand reservoir in the Bohai Sea, and the real deliverability of oil well is greatly influenced by the narrow sandbody width. Because of short testing by drill stem test (DST), the DST result cannot reflect the influence of sandbody boundary on the real deliverability, and the correction of result is necessary in general. The existing correction methods are usually based on analogy or experiences, without considering the influence of sandbody boundary on deliverablility correction coefficient. According to oil well pressure responses on the narrow channel sand bodies, this paper derives the oil production index formular of steady and/or unsteady seepage, with consideration of the channel sand boundary, further obtaining the DST result’s correction coefficient and analyzing the influencing factors of the coefficient. The results show that the narrower the channel width, the greater the difference between DST test result and actual productivity, and the more necessary the correction is; when the channel width ranges from 100 m to 300 m and the DST duration is about 0.5~15 h, the correction coefficient is about 0.3~0.7. The case study indicates that the result corrected by this method is more suitable for the actural situation in BZ25?1s oilfield Related Articles | Metrics

A New Decision-Making Method of Well Selection for Profile Control in Low Permeability Reservoir BAI LEI1,XIANG Xiaoling1,YUAN Fenggang1,MENG Yaling1, JIANG Liwu2,LIU Tongjing2 2016, 37 (2):  1-1.  doi: 10.7657/XJPG20160213 Abstract ( 71 )   PDF (300KB) ( 118 )   Save The problems encountered when applying pressure index decision?making method to well selection for profile control are analyzed, and a new reservoir measure factors (RMF) method for it is proposed by combination of derived 4 factors to describe the profile control agent injection ability and the intra?layer, interlayer and areal reservoir heterigeneities by considering dynamic and static data. The case study indicates that the RMF decision?making method is of better applicability and effect than pressure index decision?making methodapplied in A oilfield Related Articles | Metrics