Lithologic Reservoirs

Seismic reservoir is a subdiscipline of reservoir geology developed based on seismic stratigraphy, sequence stratigraphy and seismic sedimentology, while clastic seismic reservoir is an important part of seismic reservoir and is the continued research and development of above-mentioned subdiscipline. The clastic seismic reservoir and the development of related subjects are briefly summarized, and the connotation, research contents and key technologies of clastic seismic reservoir are emphatically discussed. It mainly uses high resolution 3D seismic and production seismic data, as well as geological, logging and analysis testing data, making production members and single sand body as it’s ordinarily research targets, to describe the 3D spatial configuration of clastic reservoir semiquantitatively and quantitatively, to accurately determine the heterogeneity of inter-well reservoir and qualitatively predict the reservoir property and fluid features. Based on the above-mentioned research, the reservoir lithofacies model and physical propertymodels of porosity, permeability and saturation are established. Clastic seismic reservoir is applicable not only for every exploration stages, but also for the early development stage and the target evaluation implementation stage of progressive exploration, as well as the plan adjustment in the intermediary and later stage.

Volcanic seismic reservoir

TAN Kaijun， WEI Pingsheng， PAN Jianguo， ZHANG Huquan

2010, Vol.22(4): 8–13 Abstract ( 487 ) PDF (502 KB) ( 568 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.002

Along with more and more volcanic reservoirs discovered , it is necessary to establish volcanic seismic reservoir to meet the urgent needs of petroleum exploration and development. Volcanic seismic reservoir is a branch science of seismic reservoir, and it mainly researches basin tectonic setting, volcanic lithology and lithofacies characteristics, reservoir space type, physical properties, appearance characteristics and the fluid characteristics in three-dimensional space, so as to carry out volcanic reservoir modeling. Multi-disciplinary collaborative research, such as geology, seismics and logging, is the fundamental method for studying the volcanic seismic reservoir. Rock and mineral analysis, logging lithologic identification, reservoir seismic prediction, fluid prediction, reservoir modeling and 3D visualization are six key technologies of studying volcanic seismic reservoir. Volcanic seismic reservoir can be applied to the various stages from exploration to development. However, due to the limited resolution of the existing seismic data, the recognition range of high-quality thin beds of volcanic rock is only 10 mor so, and the research of the reservoir properties and reservoir fluid properties is still in the semiquantitative stage.

Prediction technique of carbonate reservoir in Tazhong area

TENG Tuanyu， PAN Jianguo， ZHANG Huquan， LIU Jianxin

2010, Vol.22(4): 14–19 Abstract ( 597 ) PDF (700 KB) ( 793 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.003

Carbonate reservoir is characterized by rapid lateral variation, strong heterogeneity and complex accumulation conditions. Under the guidance of the theory of carbonate seismic reservoir, and based on the geophysical response characteristics of carbonate reservoir, a set of comprehensive prediction techniques for carbonate reservoir is formed, such as paleogeomorphology recovery, seismic attributes analysis, 3D seismic coherence cube analysis, spectral decomposition, pre-stack and post-stack fracture prediction, rock physics analysis and 3D visualization. These techniques guide the exploration of carbonate reservoir in Tarim Basin and promote the development of carbonate seismic reservoir, and good result is achieved in the practical application.

Using seismic rock physics modeling to predict accumulation unit of biogenetic gas in Sanhu area

ZHENG Hongjun， CAO Zhenglin， YAN Cunfeng， XU Ziyuan， SUN Songling

2010, Vol.22(4): 20–24 Abstract ( 461 ) PDF (727 KB) ( 572 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.004

Aimed at the Quaternary thin interbed of loose sand and shale in Sanhu area, the exploration of biogenetic gas is analyzed. It pointed out that to quantitatively predict the gas reservoir accumulation unit and the heterogeneity of the controlling factors is the key for looking for lowsaturation lithologic gas reservoir in the eight major slope areas. Based on the seismic data, combined with logging, geology and testing data, as well as making the two dimensional seismic data gridding, the variogram analysis and sequential indicator stochastic simulation method are applied to establish 3D petrophysical stochastic model, and the petrophysical properties body is obtained which is more sensitive to gas-bearing abnormal. The most sensitive gas threshold range of petrophysical properties body is analyzed so as to build up the gas and water identification model, and carry out the fluid substitution for the 3D model of petrophysical properties. The grid cell distribution model and seismic reservoir unit are obtained and finally the possible 3D spatial distribution characteristics of biogenetic gas reservoir can be acquired. The drilling result shows that the S wave petrophysical simulation method guided by seismic-petroleum accumulation science can predict the 3D distribution of natural gas reservoir, and good application effects are obtained.

Application of volcanic seismic reservoir to oil and gas exploration of Carboniferous in Hongche fault belt in Junggar Basin

YIN Lu， PAN Jianguo， TAN Kaijun， WANG Yanjun， WANG Bin， XU Duonian

2010, Vol.22(4): 25–30 Abstract ( 543 ) PDF (950 KB) ( 467 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.005

Under the guidance of seismic reservoir theory, the research ideas and methods of volcanic seismic reservoir are applied to targetedly select several techniques, such as three-dimensional lithologic identification, threedimensional visualization, high-resolution eigenvalue cohere, Emerge density multi-attribute inversion, multi-attribute integration, and FRACA fracture prediction. Carboniferous volcanic reservoir of Hongche fault belt in Junggar Basin is described, which promotes the oil and gas exploration of this area, and makes obvious production benefits.

Effect of slope break belt on facies and reservoirs in Erlian Basin

YI Shiwei，CHEN Yaqing

2010, Vol.22(4): 31–36 Abstract ( 447 ) PDF (761 KB) ( 609 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.006

Various slope break belts are widely developed in Erlian rifted basin. According to the genesis, they can be divided into four types, including faulted, flexural, erosional and depositional slope break. They can also be classified into antecedent, syngenetic and epigenetic slope break according to their formation time. Among them, antecedent and syngenetic slope breaks have control effect on layers, facies and sandstones. Different types of slope breaks form various styles of slope break belts laterally and experience transformation vertically. And consequently, different types of hydrocarbon reservoirs are spatially distributed in a complex pattern. Slope break belt is one key factor for the formation of hydrocarbon reservoirs. Therefore, different slope break belts should be especially distinguished. In addition, it is necessary to analyze their control effect on layers, facies, sandstones and reservoirs, so as to provide instruction for hydrocarbon exploration.

Terminal fan sedimentary system of Lulehe Formation in Qianxi area in northern margin of Qaidam Basin

MENG Wanbin， LI Min， LIU Jiaduo， XIE Yongping， MA Lixie

2010, Vol.22(4): 37–42 Abstract ( 562 ) PDF (553 KB) ( 508 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.007

The climate of the Qaidam Basin was arid to semiarid at the Cenozoic, and the strata deposits mainly are terrigenous clastics. Based on the core observation, the lithology, rock texture, sedimentary structure and the exposure evidence of Lulehe Formation are analyzed. Combined with well log analyses, it is believed that the sedimentary system of Lulehe Formation is terminal fan which formed in arid to semiarid regions. The model includes a tripartite zonation of terminal fan into feeder zone, distributary zone and basinal zone. The distributary zone mainly consists of distributary channel deposit, flood plain deposit, overbank deposit and sheet flood deposit. Feeder and distributary zone are the main deposition in Qianxi area. The subfacies distribution is analyzed and the sedimentary facies model is established. The relationship between subfacies and reservoir development is discussed and the distributary zone is the most favorable subfacies for reservoir development.

Diagenesis facies of Permian sandy conglomerate reservoir in footwall of Kebai Fault in northwestern margin of Junggar Basin

ZHANG Shuncun， LIU Zhenyu， LIU Wei， WU Tao， SHI Jian， JIA Fanjian

2010, Vol.22(4): 43–51 Abstract ( 493 ) PDF (974 KB) ( 647 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.008

According to core observation, thin section analysis, scanning electron microscope, mud logging and well logging data, the rock type and the diagenesis of Permian sandy conglomerate reservoir in the footwall ofKebai Fault are studied. The results show that the main diagenesis in the study area are compaction, cementation and dissolution. Combined with the diagenesis stage, the Permian sandy conglomerate reservoir is divided into seven diagenetic facies, they are high mature-strong dissolution facies, high mature-strong cementation facies, high mature-middle cementationmiddle dissolution facies, high mature-weak compaction facies, high mature-strong compaction facies, lowmature-weak compaction facies and lowmature-strong compaction facies. Then, the forming conditions, the features, the environment, evolutionary sequence and model of each diagenesis facies are summarized. The reservoir properties of sandy conglomerate of different diagenesis facies are analyzed, and it is suggested that the high mature-strong dissolution facies has the most favorable reservoir properties.

Identification of structural transfer zone and its application in Wuerxun Depression

ZHANG Tong, LI Zhongquan，MENG Qian，ZHU Defeng，CHEN Xiao，CHEN Junliang

2010, Vol.22(4): 52–57 Abstract ( 440 ) PDF (1330 KB) ( 563 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.009

Based on the previous studies, structural transfer zones can be divided into two types: transfer zone and accommodation zone, between which there are significant differences in the aspects of stress mechanism, structural pattern and development position. This study focuses on three large structural transfer zones of Wuerxun Depression: Tongbomiao structural belt, Bayantala structural belt and Surennuoer structural belt. The basic theory of structural transfer zone combined with seismic data is applied to analyze the structural characteristics of Wuerxun Depression. The result shows that there are obvious differences among Tongbomiao structural belt, Bayantala structural belt and Surennuoer structural belt in the aspects of structural characteristics, plane fracture characteristics and profile evolution. And it is believed that Tongbomiao structural belt is accommodation zone, while Surennuoer structural belt and Bayantala structural belt are transfer zones.

Forming mechanism and reservoir characteristics of tight quartz sandstone of coal-bearing strata of the second member of Shanxi Formation in Yulin area, Ordos Basin

ZHAO Hongbo

2010, Vol.22(4): 57–63 Abstract ( 416 ) PDF (655 KB) ( 441 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.010

The coal-bearing strata of the second member of Shanxi Formation are the main target strata for natural gas exploration in Yulin area of Ordos Basin，and the tight quartz sandstone with relatively high permeability of the second member of Shanxi Formation is the main reservoir in Yulin Gasfield. During the long diagenesis stages, the pore water in coal-bearing strata is acidity, which makes the cement in the quartz sandstone has the obvious characteristics of low content of carbonate cement, high content of siliceous cement and well developed kaolinite. The pore type of the quartz sandstone is the combination of remained intergranular pore and the secondary dissolved pore, and it is characterized by great change of pore structure, low radius of the pore throat, low stress sensitivity and well developed fracture. The research result shows that the compaction of the quartz sandstone is caused by the squeezing action and siliceous cementation during the diagenesis stage.

Reservoir property of Denglouku Formation in Changling Gasfield

LI Xiangfeng， ZHANG Chunsheng， XIAOMenghua

2010, Vol.22(4): 64–67 Abstract ( 412 ) PDF (528 KB) ( 465 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.011

Based on core and cast section analysis, it is believed that Denglouku Formation in ChanglingGasfield is low porosity and lowpermeability reservoir. The rock type is mainly fine-grained feldspathic lithic sandstone, and the rock porosityranges from2.7% to6.6%. The reservoir space ismainly secondary pore, and the pore type ismainly intergranular dissolved pore. Rock texture, sedimentary environment and diagenesis are the main factors influencing the reservoir properties. The reservoir property of branch channel is relatively good, followed by the natural levee and crevasse splay, and it is the worst in the interchannel. The compaction, pressolution and cementation do great damage to the primary porosity of reservoir, while the dissolution is favorable for the forming of secondary pore and improve the reservoir property. The diagenesis in this area ismainly destructive to the reservoir property.

Reservoir difference between east and west of Yanchang Formation in Yishan Slope, Ordos Basin

WANG Fang， HE Tao， LIANG Xiaowei， ZHEN Jing， ZHANG Dandan

2010, Vol.22(4): 68–71 Abstract ( 615 ) PDF (660 KB) ( 405 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.012

There is biggish difference in the reservoir distribution between the east and west ofYanchang Formation in Yishan Slope, Ordos Basin. In the eastern Zhijing- Ansai area, the reservoir mainly vertically distributed in Chang 6 Formation, and large area distribution in plane, while in the western Jiyuan area, multiple zones overlay in vertical and multiple rich zones developed in horizon in the same block. The analysis result shows that different migration and accumulation model cause the different reservoir distribution, which mainly displays in the following four aspects:①Different sedimentary scale. It is the main body of Shanbei multiple delta in the eastern Zhijing- Ansai area, which is large than that in the western Jiyuan area. ②Different reservoir property under the dual control of deposition and diagenesis. The reservoir property in Zhijing- Ansai area is better than that in Jiyuan area. ③Different migration pathway. The main migration pathway in Zhijing- Ansai area is connected sand body, while it is micro- fracture in Jiyuan area. ④Different migration and accumulation model. It is connected sand body and parallel migration in the eastern Zhijing- Ansai area, while it is fracture and vertical multi- points migration in the western Jiyuan area. The reservoir difference between the east and west of Yishan Slope is defined and the migration and accumulation rule is summed up, which provides significant guidance for exploration and deployment.

Characteristics of different types of slope belt and its oil-control effect in Tarim Basin

HU Yuan，ZHANG Ziming，WANG Enhui

2010, Vol.22(4): 72–79 Abstract ( 508 ) PDF (1005 KB) ( 533 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.013

Three genetic types of slope belt are identified in TarimBasin, and they are paleoslopes respectively formed during the sedimentary period, structural deformation period and preservation period, where accordingly developed different reservoirs. The first type mainly refers to the Cambrian-Ordovician platform edge slopes and Silurian-Carboniferous overlapping slopes, where reef flat reservoir and stratigraphic overlap reservoir developed. The second type consists of Caledonian-Xishan tectonic hinge zone where Ordovician karst reservoir and Silurian-Devonian stratigraphic updip pinchout reservoir developed. The last type comprises the present tectonic slopes where tectonic-stratigraphic complex reservoirs of different stages developed.

Analysis on features and formation of igneous reservoirs

ZHOU Dongli， DONG Qingsong

2010, Vol.22(4): 80–84 Abstract ( 439 ) PDF (293 KB) ( 622 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.014

Igneous reservoir has become the focus of petroleum exploration. As compared with conventional petroleum reservoirs, it has its own characteristics. In combination with a variety of igneous reservoirs have been found in the country, the lithology and features of the common igneous reservoirs are analyzed, and the controlling factors for the forming of igneous reservoirs are discussed. The property of igneous reservoirs is concerned with lithology and lithofacies. The effusion of volatile matter, denudation, condensing and contraction and dissolution in the diagenesis, the tectonic movement and the subaerial eruption environment can improve the properties of igneous reservoirs.

“Inverse ΔlogR” method and its application to evaluation of organic matter abundance of source rocks

LIU Jingdong，SUN Bo，TIAN Chao，YUAN Guowei，YU Jingfeng

2010, Vol.22(4): 85–88 Abstract ( 476 ) PDF (402 KB) ( 508 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.015

Logging method is the common method for fine evaluation of heterogeneous source rock. However, a number of factors such as the maturity and density of source rock are not considered completely by existing methods. The “Inverse ΔlogR” method which considered both the maturity of source rocks and different log responses is proposed, and took Kar 7 well as an example to calculate the organic carbon content of source rocks from 2 285 m to 2 985 m by using this method. The fact that the results are relatively consistent with the measured results proved the exactness and feasibility of this method.

Logging evaluation method for marine source rocks in middle Tarim Basin

LEI Tao， ZHOU Wen， YANG Yi， DENG Hucheng， ZHANG Guanghui， ZHAO Ankun

2010, Vol.22(4): 89–94 Abstract ( 547 ) PDF (783 KB) ( 418 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.016

The evaluation of source rocks by logging has the characteristics of low-cost, good vertical continuity and practicability. Based on physical characteristics of organic matter and theoretical model of source rocks, the conventional log response characteristics of Ordovician source rocks in middle TarimBasin are analyzed. The result shows that the organic matter abundance is closely related to the elastic parameters, uranium and thorium content ratio and ΔGR, and the crossplot between acoustic and resistivity and crossplot between density and resistivity are established to recognize source rocks quantitatively. In the aspect of organic matter abundance evaluation, ΔlogR method and BP network method are used to describe the vertical heterogeneity of source rocks, which provides a reliable basis for dividing source rocks effectively.

Several methods about converted wave static correction

ZHANG Xudong

2010, Vol.22(4): 95–99 Abstract ( 423 ) PDF (1711 KB) ( 532 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.017

There are a number of methods to solve the converted wave static correction problem. Three representative methods about converted wave static correction are selected, and these methods are respectively based on surface model, construction time control, and long and shorter wavelength statics. The three methods are studied in the aspects of principle and actual data process, which is helpful to choose proper converted wave static correction methods.

Seismic reservoir characteristics and prediction techniques for Moliqing Rift

ZHAO Wanjin， ZHANG Qiaofeng， SU Qin

2010, Vol.22(4): 100–103 Abstract ( 468 ) PDF (580 KB) ( 688 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.018

Underwater alluvial fan side and fan delta front subfacies are the main effective reservoirs ofMoliqing Rift. Moliqing Rift has the characteristics ofwell developed superimposed fan bodies, rapid variation of sand body space and complex relations among oil, gas and water, so reservoir and fluid identification is the bottleneck problemof the oil and gas exploration in this area. The early seismic reservoir prediction mainly uses seismic attribute analysis technique which is not enough to resolve the complex geologic problems in this area. Based on the reservoir sensitive parameter analysis, post-stack impedance inversion is applied to distinguish lithologies, pre-stack inversion is used to identify effective reservoir, and AVOanalysis is adopted to predict fluid medium. And good results are achieved.

Productivity prediction of Chang 8 reservoir using log data in Zhenjing Oilfield

YI Chao， DING Xiaoqi， GE Pengli， GUO Jia

2010, Vol.22(4): 104–108 Abstract ( 514 ) PDF (348 KB) ( 492 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.019

The Chang 8 reservoir in Zhenjing Oilfield in Ordos Basin is ultra-low permeability reservoir. There are various factors influencing the production with complex correlation, which brings a lot of difficulties in productivity prediction. The log response characteristics of oil layer, poor-oil layer, oil-water layer and dry layer are identified and the effective thickness of oil layer, poor-oil layer and oil-water layer are calculated. The main factors influencing the productivity are found out by testing data, by using which a correlation coefficient has good linear relation with productivity is build up, and then the productivity is predicted.

Experimental study on waterflooding in ultra-low permeability reservoirs

HE Wenxiang， YANG Yiqian， MA Chaoya

2010, Vol.22(4): 109–111 Abstract ( 577 ) PDF (361 KB) ( 470 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.020

In order to study the rule ofwaterflooding in ultra-lowpermeability reservoirs, 57 pieces of cores from3 well fields in Ordos Basin are selected to carry out experiment on waterflooding, and the relations ofwaterflooding efficiency with permeability, water injection multiple, water injection pressure and so on are studied. The selected cores mainly are ultra-lowpermeability that covers with Chang 4+5, Chang 6 and Chang 8 reservoirs. The results indicate that waterflooding efficiency increases with permeability increasing and quickly increases in lower permeability reach. It is the same situation with water injection multiple increasing, but there is lower increasing range in stage of high water-cut and no increasing until water-cut to 100%. At the same waterflooding speed, the higher the permeability is, the higher the waterflooding efficiency will be, but the waterflooding efficiency will be altering when at different waterflooding speed. There exists a best speed, and the higher the permeability is, the higher the speed is. The waterflooding efficiency generally decreases in water-free stage and increases in water-bearing stage with water injection pressure increasing and it gradually decreases when the layer gets a best pressure. The stronger the heterogeneity is, the lower the waterflooding efficiencywill be.

Deliverability equation for water-production gas well

LV Dongliang，TANG Hai，LV Jianjiang，MA Xiaoming，YU Beibei，WANG Quanlin

2010, Vol.22(4): 112–115 Abstract ( 549 ) PDF (324 KB) ( 538 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.021

The movable water existent in the strata will assemble at the bottom of gas well in the producing process, which causes the water-gas ratio rising. It will affect the output and deliverability of gas well seriously, and affect the reserve assessment and the implementation of development program. Based on the pseudosteady state flow deliverability equation, the relationship between relative permeability curves and water-gas ratio in production and the equivalent skin coefficient are applied tomodify the deliverability equation under different water-gas ratio in production, and then a new deliverability equation for gas well is obtained. The practical application shows that the modified deliverability equation is more applicable for the actual production.

Reservoir feature variation rule before and after water injection: An example from the second and third sub-members of the third member of Shahejie Formation in Gaoshangpu Oilfield of Jidong

XUAN Lingling， REN Libin， LIU Feng， YANG Xiaoliang， CHEN Fu

2010, Vol.22(4): 116–119 Abstract ( 423 ) PDF (467 KB) ( 483 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.022

It is significant to cognize the variation rule of reservoir property correctly for formulating and adjusting development policy. The reservoir features of the Es3 2+3 in Gaoshangpu Oilfield of Jidong are studied. The pore structures, reservoir properties and heterogeneity ofmain wells before and after water injection are compared. It is pointed out that the reservoir properties become better after injection, and the reservoirs with preferable properties are improved more. But it also causes more serious heterogeneity in the study area. In viewof this variation rule of the reservoir features, the idea for development is proposed.

Using second-order fuzzy multi-objective comprehensive evaluation method to predict water lock damage in low permeability gas reservoir

LV Jianjiang， TANG Hai， DUAN Yonggang， LV Dongliang， CAI Xingxing， YANG Bo

2010, Vol.22(4): 120–124 Abstract ( 423 ) PDF (345 KB) ( 422 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.023

Water lock generally exists in low permeability gas reservoir and seriously affects the exploration and development of gas reservoir. Reservoir parameter is the most important factor which affects the degree of water lock damage. However, accurate prediction of the degree of water lock damage is difficult because of the reservoir heterogeneity. 12 parameters which can reflect 4 different kinds of reservoir features including lithology, physical properties, cement type and micro-pore structure in a low permeability gas reservoir in Ordos Basin are optimized to build up the element anthology for the fuzzy multi-objective comprehensive evaluation. Different degrees of water lock damage build up the remark anthology. Complementary judgement matrix is used to determine the weight of factors, then ridge-shaped distribution function is used to define the comprehensive evaluation matrix, finally the second-order multi-objective comprehensive evaluation is formed. The evaluation results of 4 cores are consistent with laboratory test results, so the comprehensive evaluation method is accurate and valid. Based on the basic parameters of reservoir rocks, the appropriate evaluation method can be used to accurately predict the degree of water lock damage. So, the workload of gas-water flow experiments will be drastically reduced, cost will be saved, and the working system and production technology for the gas reservoir can be optimized.

Study on reservoir damage in Daniudi Gasfield

WANG Haijun， DENG Yuan， DUAN Chunjie， DIAO Zongbao， HUO Feifei， HONG Jingjing

2010, Vol.22(4): 125–129 Abstract ( 430 ) PDF (305 KB) ( 556 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.024

It’s very easy to damage reservoirs in the process of drilling and exploring, and the damage will directly affect the output of gas field. In order to reduce this damage, it is necessary to analyze the factors of reservoir damage. Taking the lowpermeability sandstone reservoirs of the first, second and third members of Lower Permian Shihezi Formation as examples, based on the test analysis, it is believed that reservoir damage mainly caused by alkali sensitivity and water lock, and there exists solid intrusion and weak salt sensitivity, water sensitivity. Correspond countermeasure is proposed so as to provide basis for field production and ensure high and stable gas field production.

Study on stress sensitivity effect on flow dynamic features of gas wells

FAN Huaicai， LI Xiaoping， DOU Tiancai， WU Xinyuan

2010, Vol.22(4): 130–134 Abstract ( 408 ) PDF (402 KB) ( 386 )

doi: https://doi.org/10.3969/j.issn.1673-8926.2010.04.024

The rock stress sensitivity will apparently affect the development performance in the process of reservoirs developing, especially in the development of low permeability reservoirs and volcanic reservoirs. The mathematical model is established by using the transient flow theory under the consideration of stress sensitivity and the skin coefficient, and the solution of the real space is obtained by means of the Stehfest numerical inversion. On the basis of the varying relation between the dimensionless rate and dimensionless time, the influences of skin coefficient, dimensionless stress sensitivity, closed boundary and constant pressure boundary on the dynamic features of gas wells are analyzed. The research result shows that to reasonably develop gas reservoirs with stress sensitivity can make sure of the gas wells and reservoirs producing normally.