Improvements to the fuzzy mathematics comprehensive quantitative method for evaluating fault sealing

Fuzzy mathematics is an important means to quantitatively evaluate the properties of fault sealing in petroleum reservoirs.To accurately study fault sealing,the comprehensive quantitative evaluation method of fuzzy mathematics is improved based on a previous study.First,the single-factor membership degree is determined using the dynamic clustering method,then a single-factor evaluation matrix is constructed using a continuous grading function,and finally,the probability distribution of the evaluation grade in a fuzzy evaluation matrix is analyzed.In this study,taking the F1 fault located in the northeastern Chepaizi Bulge as an example,the sealing properties of faults in different strata are quantitatively evaluated using both an improved and an un-improved comprehensive fuzzy mathematics quantitative evaluation method.Based on current oil and gas distribution,it is found that our evaluation results before and after improvement are significantly different.For faults in＂best＂and＂poorest＂intervals,our evaluation results are consistent with oil and gas distribution.However,for the faults in＂good＂or＂poor＂intervals,our evaluation is not completelyconsistent with oil and gas distribution.The improved evaluation results reflect the overall and local sealing properties of target zones and embody the nonuniformity of fault sealing,indicating the improved method is more suitable for evaluating fault sealing under complicated conditions.

A Quantitative Study of Fault Zone Sealing

A fault is not simply a plane, but a zone consisting of a series of broken planes or lower faults. The greater the scale of faults, the wider and more complex the fault zone is. Fault-sealing properties are influenced by the fault zone itself, whose fault displacement, depth, net-to-gross-ratio of mudstone, fault plane angle, and fault mechanical properties play important controlling roles. The sealing of hydrocarbon by the fault zone depends on whether the fault zone can form a continuous sealing zone and if the pore throats connecting those fault zones are small enough. The concept of fault zone-sealing potential is proposed here, and a quantitative formula is established by using a great amount of practical statistical data as well as the fuzzy comprehensive evaluation method, which is a comprehensive characterization parameter to judge whether or not fault zones could seal oil hydrocarbon. The greater the value of the fault zone-sealing potential, the better sealed the fault is. For example, with increasing depth, the sealing degree of the Xin 68 Fault in the Dongxin 1 oilfield changes greatly, reflecting the complexity of fault-sealing properties.

Limitation of fault-sealing and its control on hydrocarbon accumulation——An example from the Laoyemiao Oilfi eld of the Nanpu Sag

Based on previous studies on the internal structures of fault belts, the fault belts in the Laoyemiao Oilfield of the Nanpu Sag can be divided into three units, a crushed zone, an upper induced fracture zone and a lower induced fracture zone according to the log response characteristics. The upper induced fracture zone is characterized by the development of pervasive fractures and has a poor sealing or non-sealing capability. It therefore can act as pathways for hydrocarbon migration. The lower induced fracture zone consists of fewer fractures and has limited sealing capability. The crushed zone has a good sealing capability comparable to mudstone and can thus prevent lateral migration of fluid. Through physical modeling and comparing laboratory data with calculated data of oil column heights of traps sealed by faults, it is concluded that the fault-sealing capability for oil and gas is limited. When the oil column height reaches a threshold, oil will spill over from the top of reservoir along the lower induced fracture zone under the action of buoyancy, and the size of reservoir will remain unchanged. Analysis of the formation mechanisms of the fault-sealed reservoirs in the Nanpu Sag indicated that the charging sequence of oil and gas in the reservoir was from lower formation to upper formation, with the fault playing an important role in oil and gas accumulation. The hydrocarbon potential in reverse fault-sealed traps is much better than that in the consequent fault-sealed traps. The reverse fault-sealed traps are favorable and preferred exploration targets.

Quantitative evaluation of lateral sealing of extensional fault by an integral mathematical-geological model

To evaluate the lateral sealing mechanism of extensional fault based on the pressure difference between fault and reservoir, an integral mathematical-geological model of diagenetic time on diagenetic pressure considering the influence of diagenetic time on the diagenetic pressure and diagenetic degree of fault rock has been established to quantitatively calculate the lateral sealing ability of extensional fault. By calculating the time integral of the vertical stress and horizontal in-situ stress on the fault rock and surrounding rock, the burial depth of the surrounding rock with the same clay content and diagenesis degree as the target fault rock was worked out. In combination with the statistical correlation of clay content, burial depth and displacement pressure of rock in the study area, the displacement pressure of target fault rock was calculated quantitatively. The calculated displacement pressure was compared with that of the target reservoir to quantitatively evaluate lateral sealing state and ability of the extensional fault. The method presented in this work was used to evaluate the sealing of F_(1), F_(2) and F_(3) faults in No.1 structure of Nanpu Sag, and the results were compared with those from fault-reservoir displacement pressure differential methods without considering the diagenetic time and simple considering the diagenetic time. It is found that the results calculated by the integral mathematical-geological model are the closest to the actual underground situation, the errors between the hydrocarbon column height predicted by this method and the actual column height were 0–8 m only, proving that this model is more feasible and credible.

Calculating the formation period of fault lateral sealing and its application

The study aims to find out the formation period of fault traps near faults in petroliferous basins,based on an analysis of the formation period of fault lateral sealing and related influential factors.A method to calculate the formation period of fault lateral sealing(i.e.the time when displacement pressure of fault rock is equal to that of reservoir rock in fault wall with hydrocarbon migration)is established by comparing the relationship between displacement pressure and time for fault rock and reservoir rock.This method is then applied to the study on reservoirs in the 1^(st),2^(nd),and 3^(rd) members of Dongying Formation(E_(3)d^(1),E_(3)d^(2) and E_(3)d^(3))in terms of formation period of lateral sealing of F3 fault crossing the three reservoirs in the No.5 structure of Nanpu Sag in Bohai Bay Basin.The results indicate that the formation period of the lateral sealing in the studied reservoirs can date from 7.1 Ma,7.4 Ma and 9.2 Ma respectively,all prior to the hydrocarbon accumulation period(about 2.58 Ma).Hence,it can be concluded that these reservoirs are favorable for the accumulation and preservation of hydrocarbons generated from the underlying source rock E_(3)s^(3),and the method proposed is feasible in calculating the formation period of fault lateral sealing.

Methods and Case Studies of Ultra-deep Fault Seal Evaluation

Fault seals are significant for petroleum exploration and production.This study summarizes the fault sealing impacting factors,including lithological juxtaposition,mud smearing,fault rocks and the fault plane stress states,as well as evaluation methods like Allan maps and Shale Gouge Ratio(SGR).The seal evaluation for a wrench fault focuses on its particular structural features.The evaluation methods were applied to the Jinma-Yazihe structure and the Shunbei oilfield.The source rock is the Xujiahe Formation of the Upper Triassic,the reservoirs and caprocks being of the Shaximiao Formation of the Lower Jurassic.The fault sealing evaluations in major faults proved the reservoir formation processes in the wells Jinfo 1(JF1)and Chuanya 609(CY-609),based on the editions of the Allan map showing lithological juxtaposition,the calculation of SGR showing mud smear and analyses of fault stress states.The analyses of stress states were also applied to Shunbei 5 strike-slip fault in the Shunbei area in Tarim Basin.The various sections along the fault were of different mechanical properties,such as compression and extension.Petroleum exploration has demonstrated that the extensional sections are more favorable for oil accumulation than the compressional sections.These evolutionary methods and other understandings will help in analyses of deep fault sealing.

Features of the fault system and its relationship with migration and accumulation of hydrocarbon in Liaodong Bay

The fault system of Liaodong Bay developed extensively under the control of the Tanlu Fault. The fault system can be grouped into strike-slip faults of grade Ⅰ, trunk faults of grade Ⅱand branch faults （induced faults） of grade Ⅲ respectively based on its developmental scale. The faults of grade Ⅰ and Ⅱwere deep, early and large while the faults of grade Ⅲwere shallow, late and small. The formation, evolution and distribution features played a significant role in controlling the migration of oil and gas in both horizontal and vertical directions. The fluid transfer in the fault system occurred in the process of faulting. The strike-slip and trunk faults moved actively forming predominant pathways for oil and gas migration. The branch faults, with weak activity, generally controlled the development of traps and were beneficial for the accumulation and preservation of oil and gas. The faults of grade Ⅰ and Ⅱ formed the major migration pathways for oil and gas, but their fault activity rates appeared to vary along their strikes. The zones with a relatively low fault activity rate might be favorable for oil and gas accumulation. When the activities of strike-slip, trunk, and branch faults came to a halt, the fault seal behavior had a vitally important effect on the accumulation of oil and gas. The controlling role of the fault over fluid distribution was further analyzed by calculating the fault activity quantitatively.

Characteristics of fault zones and their control on remaining oil distribution at the fault edge: a case study from the northern Xingshugang Anticline in the Daqing Oilfield, China

Most major oil zones in the Daqing Oilfield have reached a later,high water cut stage,but oil recovery is still only approximately 35%,and 50%of reserves remain to be recovered.The remaining oil is primarily distributed at the edge of faults,in poor sand bodies,and in insufficiently injected and produced areas.Therefore,the edge of faults is a major target for remaining oil enrichment and potential tapping.Based on the dynamic change of production from development wells determined by the injection-recovery relationship at the edge of faults,we analyzed the control of structural features of faults on remaining oil enrichment at the edge.Our results show that the macroscopic structural features and their geometric relationship with sand bodies controlled remaining oil enrichment zones like the edges of NNE-striking faults,the footwalls of antithetic faults,the hard linkage segments（two faults had linked together with each other to form a bigger through-going fault）,the tips of faults,and the oblique anticlines of soft linkages.Fault edges formed two types of forward microamplitude structures：（1） the tilted uplift of footwalls controlled by inverse fault sections and（2） the hanging-wall horizontal anticlines controlled by synthetic fault points.The remaining oil distribution was controlled by microamplitude structures.Consequently,such zones as the tilted uplift of the footwall of the NNW-striking antithetic faults with a fault throw larger than 40 m,the hard linkage segments,the tips of faults,and the oblique anticlines of soft linkage were favorable for tapping the remaining oil potential.Multi-target directional drilling was used for remaining oil development at fault edges.Reasonable fault spacing was determined on the basis of fault combinations and width of the shattered zone.Well core and log data revealed that the width of the shattered zone on the side of the fault core was less than 15 m in general;therefore,the distance from a fault to the development target should be larger than 15 m.Vertically segmented growth faults should take the separation of the lateral overlap of faults into account.Therefore,the safe distance of remaining oil well deployment at the fault edge should be larger than the sum of the width of shattered zone in faults and the separation of growth faults by vertical segmentation.

Study on fault-controlled hydrocarbon migration and accumulation process and models in Zhu I Depression

Through the analysis of the faults and their internal structure in Zhu I Depression,it is found that the internal structure of the late fault is obviously segmented vertically.It develops unitary structure(simple fault plane)in shallow layers,binary structure(induced fracture zone in hanging wall and sliding fracture zone in footwall)in middle,layers and ternary structure(induced fracture zone in hanging wall and sliding fracture zone in middle,and induced fracture zone in footwall)in deep layers.Because the induced fracture zone is a high porosity and permeability zone,and the sliding fracture zone is a low porosity and ultra-low permeability zone,the late fault in middle layers has the character of"transporting while sealing".The late fault can transport hydrocarbon by its induced fracture zone in the side of the hanging wall and seal hydrocarbon by its sliding fracture zone in the side of the footwall.In deep layers,the late fault has the character of"dual-transportation",induced fracture zones in both sides of hanging wall and footwall can transport hydrocarbon.The early fault that only developed in the deep layers is presumed to be unitary structure,which plays a completely sealing role in the process of hydrocarbon migration and accumulation due to inactivity during the hydrocarbon filling period.Controlled by hydrocarbon source,early/late faults,sand bodies and traps,two reservoir-forming models of"inverted L"and"stereo-spiral"can be proposed in middle layers,while two reservoir-forming models of"cross fault"and"lateral fault sealing"are developed in the deep layers of Zhu I Depression.

Comprehensive evaluation on hydrocarbon-bearing availability of fault traps in a rift basin: A case study of the Qikou sag in the Bohai Bay Basin, China

An evaluation system of hydrocarbon-bearing availability of fault traps was established based on the comprehensive analysis of fault segment growth history,fine reservoir anatomy and geochemistry tracing,with the Qikou sag in the Bohai Bay Basin as target area.The displacement/separation transform and displacement gradient method were used to prove the interpretation reliability of fault traps.The method of maximum throw subtraction was used to recover the history of fault growth and determine the availability of the forming period of fault traps.Based on the quantitative relationship between shale gouge ratio and cross-fault pressure difference of known reservoirs in southern Qikou sag,the critical shale gouge ratio of fault lateral sealing was calculated at 20%,and the quantitative evaluation chart based on the relationship of"fault throw–sand-formation ratio and hydrocarbon column height"was constructed.Based on the results of reservoir fine anatomy and quantitative fluorescence tracing test shale smear factor method is suitable for evaluating the vertical sealing of faults in the caprock of the middle submember of first member of Paleogene Shahejie Formation,and the shale smear factor critical value is 3.5.The juxtaposition thickness method is suitable for evaluating vertical sealing of faults in the caprock of the second member of Paleogene Dongying Formation,and the critical juxtaposition thickness of fault is 70–80 m.By combining four factors,the availability of fault trap interpretation,the availability of the forming period of fault trap,the availability of fault lateral sealing and the availability of fault vertical sealing,the comprehensive evaluation chart on hydrocarbon-bearing availability of fault traps in Qikou sag has been established,which provides a reasonable basis for risk assessment of fault traps.

Model of Fault Controlling Petroleum Accumulation in Linshang Fault Zone,Huimin Depression

Fault controlling petroleum accumulation is mainly reflected in hydrocarbon migration and sealing in accumulation periods.By fault activity rate analysis and fuzzy comprehensive sealing evaluation in different places of Linshang Fault Zone(LFZ),LFZ controlling petroleum accumulation shows a lot of spatiotemporal differences:(1) main branch of

加权断层泥比率法(WSGR)定量判别断层封闭性——以苏北盆地高邮凹陷永安地区为例

断层封闭性评价是断块圈闭成藏条件分析的重要内容,在改进断层泥比率法基础上,提出了一种新的断层封闭性评价方法——加权断层泥比率法(WSGR)。首先,通过不同的地质模型开展断层泥比率法计算参数及影响因素分析,明确了断层断距、泥质含量及泥岩分布特征是泥岩涂抹的重要影响因素;并认为断层断距范围内,滑过目标位置的对置盘所有泥质含量都具有涂抹贡献,但不同点的涂抹贡献不同,距离目标位置越近泥质含量越高的对置盘泥岩点,其涂抹贡献越大。为此引入了一个新的表征参数——距离系数,定义为断层断距与各泥岩点到目标位置距离的差与断层断距的比值,来表征泥岩分布对泥岩涂抹的影响作用;在此基础上,构建了加权断层泥比率计算方法,定义为各点的泥质含量与距离系数的乘积之和再与距离系数之和的比值。利用加权断层泥比率法对苏北盆地高邮凹陷上含油气系统已知的油水层进行封闭性验证,认为当加权断层泥比率值大于0.6时,断层具有较好的封闭性,从而确定了该方法的封闭性判别标准。在高邮凹陷永安等地区始新统戴南组断层封闭性评价中取得了较好应用效果。

FAULTING-INDUCED PERMEABILITY CHANGE IN SHIRAHAMA SANDSTONE AND IMPLICATION FOR CO_2 AQUIFER STORAGE

The long-term safety assessment of CO2 aquifer storage requires a deep understanding o permeability evolution during inelastic deformations in sedimentary rocks.The permeability change has been measured in the entire process from elastic,plastic,post-failure to axial stress unloading for Shirahama sandstone subjected to triaxial compressions under various confining pressures.The measurements revealed that the confining pressure plays an important role in controlling inelastic deformation behavior and the tendency of the permeability evolution.In the brittle faulting regime under a low confining pressure,significant increase in permeability accompanied by dilatancy can be observed.In brittle-ductile transition regime and ductile regime,faulting or inelastic deformation does not necessarily and significantly enhance the permeability,and the permeability during deformation is lower than their corresponding initial values.Microscopic observations revealed that the two mechanisms:(1)shear-enhanced cracking,and (2)grain crushing,are responsible for these inelastic deformation and permeability evolution tendency.The presented results suggested that storing CO2 in those sites where ductile deformation prevails may be more safe.

断裂封闭性研究现状及发展趋势

断裂控油气作用主要表现在其对油气运移、聚集过程及分布规律的影响,其实质是断裂封闭性问题。断裂封闭性往往是受多种因素控制的,不同地区不同层系在不同地质时期的断裂封闭机制与封闭性主控因素差异较大。目前,断裂封闭性、封闭机理与评价方法还没有形成完整的研究体系,其评价的精度也有待提高。依据全面系统地调研断裂封闭性方面近年来的研究热点,归纳总结了断裂封闭机理,分析了断裂封闭主控因素,梳理了断裂封闭性评价方法,讨论了断裂封闭性研究中面临的实际问题,并提出了未来研究发展趋势。目前,断裂的封闭机理可以分为垂向和侧向封闭机理,前者包括断裂面封闭机理和断裂带排替压力差封闭机理,后者包括砂泥对接封闭机理、泥岩涂抹形成的侧向封闭机理和断裂带高排替压力封闭机理。断裂发育特征、断裂两盘岩性、应力场环境以及压实、胶结、溶蚀等成岩作用是影响断裂封闭性的主要因素,不同因素对断裂封闭性的作用方式不同,断裂在不同位置、不同时期的封闭性有着明显的差别。断裂封闭性评价研究方法可归结为以下4类:(1)传统地质学方法,包括定性分析和半定量分析;(2)数学地质方法,涵盖逻辑信息法、非线性映射分析法、模糊综合评判法、灰色关联分析法等;(3)构造应力场数值模拟及断裂封闭性相关参数计算法;(4)地球化学方法。碳酸盐岩地层断裂启闭机制与封闭性评价、应力和流体及其耦合作用对断裂封闭性的影响机制、多因素的断裂封闭性综合定量评价、断裂封闭性的时空演化及通源能力评估等是未来断裂封闭性研究的发展方向。

油藏型储气库断层封闭性综合评价——以堡古2区块为例

断层封闭性评价不仅对油气成藏机理与富集规律研究具有重要指导意义,更是油藏改建储气库前期地质评价的重要内容。为进一步论证堡古2油藏改建储气库的地质可行性,基于断层对上覆东三段盖层完整性的影响,建立了断层分类评价方案,从垂向与侧向2个方面评价断层的静态封闭性,利用断层活化开启压力与断层滑移失稳指数评价断层的动态封闭性,进而采用层次分析法构建断层封闭性综合评价模型,提出断层综合封闭性评价标准。研究结果表明:堡古2区块发育的11条正断层可划分为3类;断层断面正压力普遍超过8 MPa,断层两盘以砂-泥对接为主,断层泥比率(shale gouge ratio,SGR)普遍大于40%、断层开启系数(FOI)介于0.58~1.20,断层静态封闭性良好;断层活化开启临界压力超过70 MPa,明显高于地层流体压力,断层滑移指数介于0.17~0.56,均小于0.60,说明断层动态封闭性良好;11条断层封闭性综合评价指数(T)为0.93~1.15,断层封闭性良好。建立了断层封闭性综合评价标准,研究成果可为南堡凹陷乃至渤海湾盆地油气藏型储气库断层封闭性评价提供指导。

冀中坳陷文安斜坡顺向及反向断层侧向封闭性差异分析

为揭示含油气盆地中断层对油气成藏与分布的控制作用,以冀中坳陷文安斜坡为研究靶区,从顺向及反向断层控制油气富集部位及规模的差异出发,综合滑入断裂带内围岩成分及断裂带内部结构的不对称性等特征,分析不同配置类型断层的泥质含量与风险断距的差异及其对侧向封闭性的控制作用。研究结果表明:(1)在地层沉积环境相近的情况下,断层断距小于单层砂泥岩厚度和断层断距为单层砂泥岩层厚度的奇数倍时,反向断层目的点的泥质成分明显高于顺向断层;断层断距为单层砂泥岩层厚度的偶数倍时,反向断层目的点的泥质成分与顺向断层相等;在文安斜坡沙一段内反向断层的断层岩泥质含量平均值较顺向断层高6%。(2)为封闭较厚的上盘破碎带,顺向断层形成封闭时所需的临界断距明显大于反向断层,文安斜坡顺向断层风险断距的平均值约为反向断层的1.8倍。(3)理论与实例分析共同证实,反向断层更容易形成侧向封闭,这与油气主要富集在反向断层附近相吻合,但在文安斜坡内断层断距约为单层砂泥岩层厚度的偶数倍,断层岩泥质含量近似相等。这可能是导致文安斜坡顺、反向断层封闭烃柱高度近于一致的主要原因。上述结论可为油气田勘探开发提供有利的指导。

松辽盆地敖南油田CO_(2)驱油藏断层封闭性定量评价

敖南油田经历二十多年的注水开发,面临着已开发区块采油速度慢、欠注井比例高、地层压力保持水平低等问题。实施气驱开发是保持地层压力、提高采收率、降低生产成本的重要手段。但在高注入压力的条件下,注入的CO_(2)可能沿断层发生渗漏,因此,定量评价断层封闭性对于气驱油藏的开发方案设计和油田安全生产有着极为重要的意义。依据典型岩石样品排替压力和泥质含量测试结果,建立排替压力与深度、泥质含量的定量关系式,采用断层-地质模型和三维应力模型对敖南油田的断层封闭性进行了定量评价。结果表明:敖南油田的边界断层原始渗漏临界压力为0~12 MPa,渗漏风险区分布在储层砂岩对接程度较高的井组和不同断层交界附近,其临界压力为0~4 MPa;在井位优化设计时风险区附近要预留安全距离,注气井要避开高渗漏风险断层,或在注入井与断层间设计采出井以降低储层压力,降低CO_(2)沿断层渗漏的风险。研究结果可以为CO_(2)驱油藏的开发方案设计提供有效依据。

断面有效正应力对断层侧向封闭能力的控制作用

小位移断层的侧向封闭性决定断层圈闭富集油气的能力,随着油气勘探技术理论的发展,曾被忽略的小位移断层在油气勘探和开发过程中的作用日益突出。为了明确小位移断层的内部结构特征及其对断层侧向封闭性的影响,应用自主研发的高压低速环形剪切装置,以断面有效正应力为变量,对高孔隙度纯净砂岩开展环形剪切物理模拟实验,分析断面有效正应力对断层侧向封闭性的影响。结果表明:断裂在高孔隙纯净砂岩内以碎裂作用机制为主,形成典型的碎裂型断层岩,其渗透率明显降低,是导致同层砂岩对接段侧向封闭的根本原因。在其他因素固定的条件下,断面有效正应力越大,断层岩碎裂程度越大,颗粒直径和孔隙度越小;岩石颗粒的破碎及碎屑基质的填充导致断裂带孔隙度和渗透率明显降低。断面有效正应力是小位移断层侧向封闭能力的主要控制因素,小位移断层具有富集油气的潜力。研究结果对裂陷盆地断块油气藏勘探开发具有重要的指导意义。

储气库运行上限压力的确定方法及在板中北储气库的应用

大港油田板中北储气库位于板桥断层上升盘,为断层切割的半背斜构造,属于断块型储气库,断层和盖层的承压能力决定了储气库运行的上限压力。针对缺乏考虑力学完整性的储气库上限压力的研究现状,从地质力学角度出发,综合三维地震解释成果、XMAC测井地应力解释成果、岩石力学测试等资料,基于岩石脆性破裂理论对研究区盖层的水力封闭能力和断层的稳定性进行了评价,以确定考虑力学完整性的储气库安全运行上限压力。结果表明:板中北储气库盖层水力封闭能力上限为39.30 MPa,断层稳定性薄弱点位于2条断层的交叉位置,最小活化压力为30.57 MPa;综合盖层水力封闭能力上限和断层稳定性可知,板中北储气库运行上限压力为30.57 MPa,而设计运行上限压力为30.50 MPa,设计较为合理。研究成果对于储气库上限压力的设计具有指导意义。

多参数评价准噶尔盆地车莫古隆起北部断层封闭性

车莫古隆起北部地区在侏罗系中相继发现了一系列断块油气藏,断层封闭性的好坏控制了研究区油气的生成和聚集。为了研究多类型断层封闭能力,利用地震、测井等资料,采用断面正应力、断面紧闭指数、泥质含量和泥岩削刮比等参数,针对不同性质的断裂优选多种参数组合方式,开展断层封闭性评价,结合3Dmove软件虚拟井法进行封闭性分析,最后运用模糊数学评价方法得到综合评价指标,总结影响断层封闭能力的各种因素,预测有利断层。研究结果表明,车莫古隆起北部地区断层封闭性中等偏差,其中,现今封闭性好于成藏期。断层封闭能力主要受走向、规模以及泥岩与砂岩的厚度影响,与断面正压力无明显关系。沙窝地地区断层封闭性好于莫西庄地区,庄北地区断层封闭性最差。通过多种方法综合研究车莫古隆起北部断层封闭性,对预测有利断层、寻找油气富集的断块油气藏具有重要意义。