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01 January 2019, Volume 37 Issue 4 Previous Issue    Next Issue

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Discovery and Hydrocarbon Accumulation Mechanism of QuasiContinuous HighEfficiency Reservoirs of Baikouquan Formation in Mahu Sag, Junggar Basin ZHI Dongming 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160401 Abstract ( 142 )   PDF (300KB) ( 608 )   Save In recent five years, great breakthroughs have been made successively in the Lower Triassic Baikouquan formation in hydrocarbon?rich Mahu sag in the northwestern margin of Junggar basin, and the above?source quasi?continuous oil reservoirs with the reserves over hundreds of millions of tons are firstly discovered, which should be attributed to the changes of thoughtway from structural reservoir exploration to lithological?stratigraphical reservoir and continuous reservoir exploration. Composite analysis on hydrocarbon accumulation mechanism shows that high?quality Carboniferous?Permian source rocks are developed in hydrocarbon?rich Mahu sag, which is favorable for oil generation; high?quality reservoirs and structural?lighological traps of fan?delta front facies are developed in Baikouquan formation, in which faults connect the source rock and the reservoir, which helps hydrocarbon accumulation; gentle structures with good top and bottom conditions in Baikouquan formation are in favor of hydrocarbon enrichment; abnormally high pressure and fractures occur in Baikouquan formation, and the oil here is of good quality and reservoir sweet spots are developed, which is good for high oil production. Therefore, quasicontinuous reservoirs with the reserves of hundreds of millions of tons in Baikouquan formation in Mahu sag are characterized by extensive oil distribution, local oil enrichment, jointly controlled by nose?like structural belts and favorable belts in delta front as well as faults, high?efficiency accumulation and great prospecting potential, which can be an important supplement to continuous?reservoir exploration and research in the world. It is suggested that Huangyangquan fan, Madong fan and Xiayan fan with relatively low exploration degree should be focused on for further petroleum exploration at present Related Articles | Metrics

Genetic Mechanism of Intragranular Fractures in LowPermeability Sandy Conglomerate Reservoir and Their Significance in Petroleum ExplorationA Case Study from Triassic Baikouquan Formation in Mahu Sag, Junggar Basin XU Yang, MENG Xiangchao, LIU Zhanguo, SHAN Xiang 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160402 Abstract ( 57 )   PDF (300KB) ( 332 )   Save The sandy conglomerate reservoirs of Baikouquan formation of Mahu sag in northwestern margin of Junggar basin are low?porosity and low?permeability reservoirs, where the intragranular fractures act as the important flow paths. Less researches have been made in terms of genetic mechanism and development of intragranular fractures at home and abroad. This paper systematically analyzes the identifying characteristics, genetic mechanism, development process and distribution of intragranular fractures in low?porosity and low?permeability sandy conglomerate reservoirs, according to themacroscopic and microscopic characteristics of intragranular fractures development, combining with drilling and seismic data, by means of relationship characterization of the palaeotectonic stress value?the intragranular fractures, and intragranular fracture physical modeling experiment. It is considered that the intragranular fractures in Baikouquan formation are structural?diagenetic fractures genetically, the generation of the fractures is related to the properties of compression, shearing and torsion,internal defect of grains, tectonic stress and stress effect; the main influence of intragranular fractures on the reservoir is to improve reservoir permeability, and the effective configuration of intragranular fractures in coarse grains?intergranular matrix pores among sand grainsmicrofissures is the key factor to generate high?quality and high?efficiency reservoirs of Baikouquan formation; the intragranular fractures are mainly distributed in Middle?Lower Triassic Baikouquan formation vertically and mostly in Wuerhe?Xiazijie faulted belt in plane.The development degrees of intragranular fractures in Karamay?Baikouquan and Wuerhe?Xiazijie faulted belts are different due to the changes of stress effect mode and rigid grain content. Constrained by thrust fault distribution, the development degree of intragranular fractures is weakening from the faulted zone to slope area, but tends to increase at strike?slip faults Related Articles | Metrics

Controls of Tectonic Activity on Alluvial Fan Deposits and Hydrocarbon Accumulation: A Case Study of Permian and Triassic Alluvial Fans in Northwestern Margin of Junggar Basin YIN Senlin1, TANG Yong2, HU Zhangming3, WU Tao2, ZHANG Lei2, ZHANG Jiyi1 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160403 Abstract ( 81 )   PDF (300KB) ( 530 )   Save The coupling relationship between tectonic activity and alluvial fan deposits is one of the hot spots and difficulties in tectonosedimentology research. Uncommon and widespread sandy conglomerate bodies are developed along the faulted zone in the northwestern margin of Junggar basin. Therefore, studies on the controls of tectonic activity on alluvial fans and hydrocarbon accumulation are of great theoretical and practical significance. Using the data of cores, logging and seismic profiles, this paper studies the distribution of structurecontrolled alluvial?fan sandy conglomerate bodies, and the hydrocarbon accumulation patterns combined with related oil and gas accumulation data. It is shown that the stacking pattern of alluvial fans is closely related to the activity of contemporaneous faults, and there are 3 typical distribution patterns of the fans under the control of contemporaneous faults, which include the retrograded alluvial fans against the source direction and controlled by normal comb?like fault combination, the laterally superimposed alluvial fans and vertically stacking alluvial fans controlled by reverse comb?like faults and crossing faults, and the progradational alluvial fans controlled by preceding faults. Tectonic activity has significant impact on provenance, landform and local climate during the formation of these alluvial fans. These factors jointly control the development and sedimentary sequence differences of alluvial-fan sandy conglomerate bodies at different positions of the structures. It is concluded that alluvial-fan sandy conglomerate reservoir forms under the effects of both structure and lithology, which is characterized by one reservoir in one fan, several reservoirs in one fan, and one reservoir in several fans Related Articles | Metrics

Pore Structures and Controlling Factors of Middle PermianLower Triassic Sandy Conglomerates in Northwestern Margin of Junggar Basin CHEN Nenggui, GUO Mozhen, MENG Xiangchao 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160404 Abstract ( 68 )   PDF (300KB) ( 310 )   Save Pore structure types and the controlling factors are difficulties in sandy conglomerate reservoir research and also the basis for sandy conglomerate reservoir evaluation and prediction. Based on the data of high?resolution CT imaging scanning, petrophysical properties of cores, formation and production tests, and integrated with petrological?mineralogical characteristics of sandy conglomerate, a research on pore structures and the controlling factors is carried out for Middle Permian?Lower Triassic sandy conglomerate reservoirs in northwestern, margin of Junggar basin. Standards for pore structure classification in sandy conglomerate reservoirs are established using pore throat radius, porosity and permeability, then the pore structures in the study area are divided into 4 types such as good, medium, poor and tight pore structures, and 3D quantitative pore?structure numerical models are established for each kind of pore structure. The result shows that the pore structures of the sandy conglomerate reservoirs are mainly controlled by shale content, debris content of volcanic rocks, compaction and cementation, among which the former two are dominant controlling factors. With the increase of shale content and debris content of volcanic rocks, compaction and cementation become stronger and pore structures become poorer. Sandy conglomerate with good?medium pore structures mainly occurs in the braided?channel of fan?delta plain and underwater distributary channels of fan?delta front in tractive current depositions; that with poor pore structures develops in the debris flow of fan delta; that with tight pore structures occurs in mud?rich fan?delta distributary channel and strong cemented zone of the tops and bases of sandbodies Related Articles | Metrics

Formation of Ordovician Shale Gas and Prediction of Favorable Zones in Tarim Basin QIAO Jinqi1, LIU Luofu1, SHEN Baojian2, HU Qing1 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160405 Abstract ( 91 )   PDF (300KB) ( 83 )   Save Based on the systematic study on lithology, geochemical characteristics, reservoir characteristics and gas?bearing properties of Ordovician shale in Tarim basin, the paper considers that the Ordovician strata are extensively developed in this basin, in which organicrich shales include black carbonaceous shale, calcareous and siliceous shale. These shales are mainly found in Saergan formation ( 7~22 m in thickness) in the western Tarim basin and Heituao formation (40~60 m in thickness) in the eastern Tarim basin. The kerogen type of Saergan formation is Type Ⅰ and Ⅱ and that of Heituao formation is Type Ⅲ, all of which are good?high quality source rocks with the thermal evolution degree of high?matured to over?matured stage. The shale is dominated by quartz, the clay minerals are dominated by illite, the pores by mesopores and macropores with developed microfissures, and the brittle mineral content of the shale is high. Detrital minerals of the shale have good adsorption property. The gas content of downhole samples shows a positive correlation to organic carbon content, but the correlation of outcrop samples is not obvious due to weathering. The selected Middle?Lower Ordovician shale gas areas are located in the eastern Tarim basin with an area of about 1 582 km2, in Weili county with an area of about 1 058 km2, respectively. The estimated oil and gas reserves amount to 17 814×108 m3 Related Articles | Metrics

Controlling Effects of Ordovician Karst Paleogeomorphology on Reservoirs in Tahe Oilfield,Tarim Basin HAN Changcheng1, LIN Chengyan1, LU Xinbian2, WEI Ting3, REN Lihua1, ZHANG Xianguo1 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160406 Abstract ( 48 )   PDF (300KB) ( 119 )   Save Using the data of core, thin section, drilling, logging and seismic profile, the mark of palaeokarst identification is analyzed; the Ordovician karst palaeogeomorphology is restored with impression method and residual thickness method combined with unconformity structures; karst paleogeomorphic units are classified and their controlling effects on reservoirs are analyzed. In the 4 secondary paleogeomorphic units such as karst highland, karst gentle?slope, karst steep?slope and karst basin, 4 tertiary paleogeomorphic units (monadnock, tableland, level terrace and clough) are further classified quantitatively. The favorable areas for karst reservoir development are monadnocks and tablelands in the karst gentle?slope, the ends and flanks of the clough, and the tablelands and level terraces in the karst steep?slope Related Articles | Metrics

Characteristics and Exploration Potential of UltraDeep Cretaceous Reservoir in Kuqa Depression, Tarim Basin ZHANG Ronghu1LIU Chun1YANG Haijun2ZHANG Huiliang1WANG Junpeng1, ZENG Qinglu1 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160407 Abstract ( 57 )   PDF (300KB) ( 162 )   Save The Cretaceous reservoir in Kuqa depression of Tarim basin is a set of ultra?deep, ultra?high pressure, high temperature and lowporosity fractured sandstones. To identify characteristics, genesis and exploration potential of the reservoir, an integrated research is performed using structural evolution reconstruction and systematical characterization and based on the data of confocal laser scanning, industrial CT, high?pressure mercury injection, SEM, carbon and oxygen isotopes analysis, physical properties of full?diameter cores, electron microprobe spectroscopy and so on. The study shows that the braided delta?front sand bodies are superimposed and distributed continuously in Cretaceous Bashijiqike formation of Crassus deep zones with the thickness of 150~250 m; in ultra?deep layers, residual primary porosity and dissolved pores are relatively developed, netlike, high?angle, filled to semi?filled fractures are developed, too. The reservoir generally belongs to low?porosity, medium?low permeability in nature; the genesis mechanism is dominated by 3 mechanisms such as shallow burial during the early and middle stages, celling structure of nappe?type, gypsum?salt rocks during the late stage and intercoupling and superimposition between dissolution during epidiagenetic stage to early diagenesis stage and tectonic compression at the late stage; the effective reservoir thickness ranges from 80 m to 200 m and the relatively high quality reservoir thickness reaches to 30~90 m, which are mainly continuously distributed in the areas superimposed by underwater distributary channel, E?W axis of structural anticline and zone within 220 m to unconformity surface. The effective reservoirs could still exist in the burial depth of 8 000 m. All the areas may have natural gas reserves potentials of trillions of cubic meters by estimation Related Articles | Metrics

Characteristics of Vertical Zonation of Bashijiqike Reservoir by Stress Intervals in Wellblock Keshen5 in Kuqa Depression, Tarim Basin SHI Lingling, TANG Yangang, WANG Bin, WANG Zuotao, WEI Hongxing, ZHOU Lu 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160408 Abstract ( 66 )   PDF (300KB) ( 168 )   Save Through analysis on the experimental data of core, common thin section, cast thin section, SEM and high?pressure mercury injection, correlation and analysis on lithological features, reservoir space types, physical properties and pore structures are carried out for each stress intervals of Bashijiqike formation in Wellblock Keshen?5 in Kelasu structural belt, Kuqa depression. The result shows that different stress intervals are similar to each other, all of which are dominated by lithic feldspar sandstone cemented by calcite, but the clastic particles in extensional stress interval are mainly spot and spot-line contacts and that in transitional interval are dominated by line contact, that in transpressional interval are in directional alignment; matrix pore types are different in different stress intervals, the average reservoir porosity gradually decreases and the average permeability becomes larger from the extensional stress interval to the transpressional interval.The pore structure varies in different stress intervals, the capillary pressure curves of the reservoirs are mainly Type Ⅰ and Ⅱ in the extensional interval, which is featured with low displacement pressure and median pressure, high mercury?intrusion saturation, large average porethroat radius, even pore throats and good connectivity; the capillary pressure curves of the reservoirs are dominated by Type Ⅳ in the transpressional interval, which is featured with small pore?throat radius, poor pore?throat sorting and connectivity, irregular distributed displacement and median pressures due to the influence of microcracks; the reservoirs in transitional interval have moderate features between extensional and transitional intervals. The results of the study verify the vertical zonation of Bashijiqike reservoir in Wellblock Keshen?5,and change the conventional method for lithology?based reservoir correlation and analysis Related Articles | Metrics

Quantitative Evaluation of HighQuality Source Rocks in Liaodong South SubSag in Bohai Bay Basin ZHAO Dijiang, WEI Ajuan, GUO Yonghua, FU Li, WU Qingxun, ZENG Jinchang 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160409 Abstract ( 64 )   PDF (300KB) ( 212 )   Save The Liaodong south sub?sag in Bohai Bay basin is an area with shallow burial, complicated structural evolution, low exploration degree, and unclear resource potentials up to now, so evaluation of the source rocks in this area is extremely necessary. Based on geochemical and paleontological analysis, the main hydrocarbon?generating sequences are determined in this south sub?sag. It is considered that the Sha?1 to Sha?3 members of the Oligocene Shahejie formation are of high abundance and good type of organic matter as well as high maturity of source rocks, which could be as the major source rocks in the study area; the Sha?4 member to Kongdian formation are of relatively low abundance of organic matter with relatively high maturity and extensive distribution, which could be as the potential source rocks; the Dong?3 member of the Oligocene Dongying formation has relatively low maturity of the source rocks, so it provides less contributions to hydrocarbon generation. Based on logging data and multi?attribute seismic inversion processing, quantitative evaluation is made for each high?quality source rock development scale, and the result shows that several series of source rocks exist in the south sub?sag, which are widely distributed and have greater hydrocarbon?generating potentials, most being of petroleum exploration prospect. The high?quality source rocks in the north part of it are significantly thicker than that in the south part, which is the hydrocarbon?generating center in the study area. The source rocks in the south part are in beaded distribution along the strike?slip fault and controlled by the fault Related Articles | Metrics

Review of Lee’s Discovery Process Model for Petroleum Resources and Establishment of Prediction Model CHEN Yuanqian, TANG Wei 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160410 Abstract ( 61 )   PDF (300KB) ( 180 )   Save The discovery process model in Chapters 4 and 7 of Lee’s Statistical Methods for Estimating Petroleum Resources is the important theoretical foundation to evaluate oil and gas resources. Lee uses probability density functions of Lognormal distribution, Weibull distribution, Gamma distribution, Logistic distribution and Pareto distribution to describe the discovery process of unimodal cyclic resources in a petroliferous basin. But, it is found that except for Lognormal distribution, other 4 distributions are all wrong, which will inevitably influence the accuracy of the model. Additionally, dimension transformation must be performed to establish a reliable prediction model because the probability density function is a dimensionless quantity of 0~1. But Lee never mentions the dimension transformation of the probability density functions in his monograph. Based on comparison, the authors point out the mistakes of probability density functions introduced by Lee, and establishes a prediction model to evaluate petroleum resources through dimension transformation and derivation Related Articles | Metrics

Relationships among 4 Types of WaterDrive Characteristic Curves and Arps Decline Curve YAO Jian 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160411 Abstract ( 135 )   PDF (300KB) ( 264 )   Save Water?drive characteristic curves and decline curve as the methods of production performance evaluation play significant roles in recoverable reserves evaluation and development index prediction in developed oilfields. But direct relationship between the two methods cann抰 be established due to different theoretical bases of them. Oil production vs time expression is derived from Arps decline formula in this paper and it is considered that if an expression related to transient decline rate and oil production could be obtained from the deformation of a water?drive characteristic curve expression, there must be a kind of relationship between the water?drive type curve and Arps decline curve. 4 commonly used water?drive characteristic curves are selected. Assume that liquid production doesn’t change with time,take the derivative of time twice, expressions of the relationships among the 4 type curves in regard to transient decline rate and oil production are obtained. The decline trend of Type B water?drive type curve is in accordance with that of harmonic decline, the decline trend of Type C is matched with that of hyperbolic decline when n=0.5. Type A and D curves are similar to Arps decline curve only when the reservoir water cut is relatively high. Based on the expressions of transient decline rate and oil production of the 4 water?drive characteristic curves, a method is established for development index prediction, whose high accuracy has been proved by some cases Related Articles | Metrics

New Model for Water Cut Forecasting in Waterflooding OilfieldsEstablishment and pplication ZHOU Peng 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160412 Abstract ( 69 )   PDF (300KB) ( 182 )   Save Because water cut is an important index to reflect production performance of water?flooding oilfields, water cut forecasting based on available production data is a very meaningful work. Conventional methods for it are hard to be used to establish relationships between the changes of water cut and production time, and solving the parameters in conventional models are relatively complicated. On the basis of a growth curve model for field development index forecasting, a new model is established to forecast water cut changes with production time . The new model is characteristic of simple expressions, easily getting parameters and more accurate prediction. Case studies from 2 reservoirs show that the forecast results obtained by the model are more accordant with the actual production performances, and the new model is more practical Related Articles | Metrics

Characteristics of Damage of Guar Fracturing Fluid to Reservoir Permeability XU Linjing, ZHANG Shicheng, MA Xinfang 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160413 Abstract ( 62 )   PDF (300KB) ( 307 )   Save Conventional guar fracturing fluid will damage core permeability after gel?breaking, and influence oil well productivity after fracturing stimulation. Based on the analysis on guar fracturing fluid compositions, dynamic and static adsorption experiments and core?damage experiment are carried out for artificial cores and natural cores. Artificial core?damage experiment result shows that the damage of guar breaking liquid can be classified as water damage and guar retention damage, of which water damage is more serious than guar retention damage. Adsorption experiment result shows that the retention of the guar molecules of gel?breaking liquid in pores of cores can be classified into adsorption and trapping, accounting for 43.6% and 56.4% in average, respectively. The result from natural core damage experiment in Yuanba area also shows that the gel?breaking liquid in guar fracturing fluid has an aqueous?phase damage to natural cores. Guar molecules after gel?breaking have less impact on permeability of natural cores compared with aqueous?phase damage Related Articles | Metrics

Damage of Polymer Acid Viscosifier to Reservoirs LIN Xin1,2, ZHANG Shicheng2, LI Xiaogang3, ZHANG Rusheng2, CUI Jia2 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160414 Abstract ( 70 )   PDF (300KB) ( 175 )   Save Commonly?used acid viscosifiers during acid fracturing are mostly high?molecular polymers of polyacrylamide. These viscosifiers still have some viscosity after degradation and remain in formations after acid fracturing, which may cause damages to reservoirs and influence the acid fracturing effect directly. 3 types of residual acids of polymer acid viscosifier (gelled acid, crosslinked acid and temperature?controlled sticking acid ) are prepared, and experiments on the damages of these 3 residual acids to high?permeable and low?permeable carbonate cores are carried out. The results show that all the 3 residual acids have greater damages to matrix permeability of high?permeable carbonate cores than that of low?permeable cores, i.e., the larger the initial core permeability and, the more developed the core pores are, the more serious the damage from products degraded by large?molecule polymers will be. However, the filter cakes produced by the 3 residual acids have relatively low damages to core permeability, which might not be the key factor for the reservoir damage Related Articles | Metrics

Impact of Sand Grains on Reservoir Permeability Based on Digital Cores XUE JiankangWANG YudouWANG DianshengZHOU WeiWANG Xueying 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160415 Abstract ( 63 )   PDF (300KB) ( 143 )   Save Accurate understanding of the effect of sand grains on reservoir permeability is significant for reasonable development of sandy conglomerate reservoirs. On the basis of CT scanning images of cores, digital cores of sandy conglomerate are constructed with sand?grain imbedding method, the corresponding pore network model is extracted with the maximum ball method and the impact of sand grains to permeability and residual oil saturation of sandy conglomerate is studied using percolation theory. The result shows that the existence of sand grains will decrease core permeability and increase residual oil saturation; with sand grains moving towards core outlet end, core permeability and residual oil saturation will gradually decrease; the increase of sand grain size will block flow paths among pores, which will result in the decline of core permeability and increase of residual oil saturation. Then a relation model between core permeability and micro?pore structural parameters has been established and the prediction result obtained from the model shows good consistency with the percolation modelling result, the relative errors of core permeability and residual oil saturation are less than 7.6% and 2.8%, respectively Related Articles | Metrics

Method for Wavelet Function Selection During SurfaceWave Attenuation Processing YANG Shunliaoa, GUI Zhixianb, ZHANG Zhengbinga 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160416 Abstract ( 59 )   PDF (300KB) ( 206 )   Save Based on the discussions on the principles of surface wave attenuation processing in wavelet domain, it is concluded that good separability of wavelet decomposition result is needed during surface wave attenuation processing. Because support length decides local features and vanishing moment decides the energy concentration degree of low?frequency and low?wave?number components, a symmetrical wavelet function principle that short support length and high vanishing moment should be chosen is determined, and Symmlet wavelet function is considered as the optimal wavelet. Surface?wave attenuation degree and influence of reflection wave are analyzed regarding surfacewave attenuation processing results obtained from actual seismic data and synthetic seismogram, which validates the method for wavelet function selection Related Articles | Metrics

Lithology Identification of Carboniferous LowRadioactivity Igneous Rocks by Logging Data in Zhongguai Swell, Junggar Basin LI Jing 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160417 Abstract ( 56 )   PDF (300KB) ( 143 )   Save The lithology of Carboniferous igneous rocks in Zhongguai swell of Junggar basin is complicated and characterized by rapid lateral variation, large vertical thickness and low radioactivity, so natural gamma logging can not be used to accurately identify the lithology.The main rock types are analyzed based on core observation and thin section examination. Analyses on rock genesis and components are performed with elementary capture spectroscopy logging (ECS) and the mass fraction crossplot of SiO2, Fe2O3 and TiO2 is established to classify chemical component of igneous rocks. According to texture and structure information reflected by FMI logging, an imaging mode chart is established to further identify the lithology. Based on the above, conventional logging response features are analyzed for igneous rocks with different lithologies, structures and mineral compositions. Then the ECS and FMI identification results are integrated with the conventional one, analyzing the conventional curve sensitivity and establishing neutron porosity?density crossplot, finally, the conventional logging curves can be used to classify the lithologies of igneous rocks Related Articles | Metrics

Optimized Processing of PreStack Gathers and Its Application in AVO Analysis LI Yuanjuan1WANG Zesheng2YAN Jianguo1WU Jie1YAN Xiaowei1XU Song1 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160418 Abstract ( 77 )   PDF (300KB) ( 222 )   Save Focusing on amplitude?preserving processing, the authors establish a gather optimization processing procedure of actual seismic data to optimize pre?stack common?reflection?point (CRP) gathers, by which energy loss compensition can be made using inverse Q filtering, wavelet stretch distortion correction can be made by spectrum equilibrium, and residual moveout removing will be realized by waveform matching approach, and good effects have been gained after the optimized procedure was applied to AVO analysis of carbonate buriedhill reservoirs in Bohai Bay basin. This paper indicates that the optimized gather processing technology can better highlight the AVO response characteristics of subsurface strata Related Articles | Metrics

Analysis on Sensitivity of Influencing Factors of Rock Electrical Properties Based on the Orthogonal Analysis DONG HuaiminSUN JianmengYAN WeichaoCUI Likai 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160419 Abstract ( 65 )   PDF (300KB) ( 57 )   Save Based on the analysis of influencing factors of rock electrical properties, this paper proposes using orthogonal analysis to identify sensitivities of the influencing factors, using orthogonal matrix design to analyze horizontal associations of the influencing factors, and using variance component and trend analysis approaches to quantitatively evaluate the sensitivities by which dominant and secondary factors can be distinguished. Case study from selected core samples shows that rock electrical properties exhibit different sensitivities to different influencing factors, and the sensitivity analysis result is in accordance with that of the numerical simulation of rock electrical properties Related Articles | Metrics

Advances of Fast StartUp Technologies of SAGD Process for Dual Horizontal Wells YANG Hong, HE Xiaodong, LI Chang, CHEN Sen, YOU Hongjuan 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160420 Abstract ( 72 )   PDF (300KB) ( 155 )   Save Focusing on the long circulating preheating time and large steam consumption of dual horizontal wells during the start?up phase by steam assisted gravity drainage (SAGD) process, this paper introduces the mechanisms of 4 fast start?up technologies of SAGD process for dual horizontal wells, which include solvent assisted start?up, foam assisted start?up, electromagnetic heating start?up and stress expanding start?up, and also analyzes each advantages and existing problems in their applications. It is suggested that the stress expanding startup technology has obvious advantages and further related researches should be made to improve its technical adaptability, and the combination of these fast start?up technologies will be an effective way for improving the effects of start?up phase． Related Articles | Metrics

Petroleum Reservoir Characteristics and Favorable Exploration Areas in Faulted SlopeBreak Zone of Bozingen Graben, Kazakhstan YU Haoye1, ZHAO Weijun2, OU Yaping1, JIANG Tao1, GUO Yong1 2016, 37 (4):  1-1.  doi: 10.7657/XJPG20160421 Abstract ( 50 )   PDF (300KB) ( 82 )   Save Taking Bozingen graben in the South Turgay basin of Kazakhstan as an example, a comprehensive study on its classification and the relationship between the graben and the oil reservoirs is conducted based on the reservoir rocks, strata, structures and their locations in faulted slope?break zone. The high?level slope break where incised valleys are mainly found is featured with thin layers, undeveloped reservoir rocks and dominated by faulted?block reservoirs. The medium?level slope break with relatively complete strata and developed reservoir rocks is dominated by faulted?block reservoirs and structural?lithological reservoirs, where broad and gentle gullies are mainly found. Located in the hydrocarbon source rock development area, the low?level slope break is dominated by condensate gas reservoirs in lithological traps, where lowstand fans are mainly found and the reservoir rocks are not developed. Based on the characteristics of these 3 slope breaks,it is considered that the gullies in the medium?level and high?level slope breaks are the favorable areas for oil reservoir exploration, and the low?level slope break is the favorable area for condensate gas reservoir exploration Related Articles | Metrics