【作者】 龚建洛；

【导师】 张金功；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2013， 博士

【摘要】 含油气盆地的升降差异与断裂、裂缝的关系对油气藏的形成具有重要的控制作用,目前对此的研究较为薄弱。本文对沾化凹陷沙三中段、沙三上段、沙二下段、沙二上段、沙一段、东营组、馆陶组、明化镇组及第四系的沉积与沉降特征和东营组沉积末期地层剥蚀征进行了分析,在此基础上分析沾化凹陷古近系主力烃源岩(沙四上-沙三中段)在沙三上段、沙二下段、沙二上段、沙一段、东营组、馆陶组、明化镇组沉积期及第四纪的沉降及抬升剥蚀的差异。利用沾化凹陷地震资料分析了断裂与古近系主力烃源岩沉降差异之间的关系,通过岩心、薄片中裂缝发育特征观察及岩石压缩-回弹、破裂力学实验,分析了沉降差异与裂缝的形成和演化的关系,利用渗透率测试实验比较了不同输导介质的输导性能。在以上研究基础上结合沾化凹陷古近系和新近系油气运移驱动力的分析,对沾化凹陷古近系和新近系与裂缝有关的和与断裂有关的油气藏的形成特点进行了初步分析。取得了以下认识：1沾化凹陷古近系-新近系主力烃源岩沙四上-沙三中段在沙三上段至沙一段沉积期,沉降最大区主要位于渤南-孤北和富林-孤南一带；东营组沉积期至第四纪,沉降最大区位于渤南-孤北、桩西和孤南一带。沉降最大区在沙一段沉积期已超过1200m,在东营组沉积期渤南-孤北和孤南一带超过1800m,桩西一带达到1300m；在馆陶组沉积期超过2000m,在第四纪超过3400m(该时期是主力烃源岩大量生成油气的时期)。整体上,沉降最大区沙三中段至沙一段沉积期相对较为稳定,自东营组沉积期至第四纪,沉降最大区逐步向凹陷东南部迁移,沉降幅度向盆地西北方向逐渐减小。现今的最大构造埋深区主要主要位于渤南-孤北、桩西和孤南一带,是在自沙三中段沉积期以来沉降基础上,继承发展而形成的。2沾化凹陷古近系-新近系主力烃源岩层最大埋深区与断裂的关系可以分成两类：第一类为断裂走向上深切最大埋深区或与埋深等值线相交,第二类为断裂没有深切最大埋深区并与埋深等值线近于平行。3盆地沉降过程中,岩石的演化分为塑性压实、弹塑性压缩和破裂三个阶段。沾化凹陷古近系-新近系地层中发育有平行层面裂缝、斜向裂缝和垂直裂缝,其中部分平行层面裂缝有滑移特征,多见于泥质岩。裂缝的组合以“T”或“工”型为主。沾化凹陷泥质岩裂缝发育深度一般在2000m以下。在沾化凹陷的拉张埋藏过程中,岩石在水平方向的伸展能力的差异是形成平行层面的裂缝主要原因；随着上覆岩层压力的增大,岩石横向上的伸展能力受到限制时就会在岩石中产生垂向裂缝;当垂向压力不均衡时,就容易形成斜向裂缝。当盆地发生抬升剥蚀时,不仅可诱发裂缝的发育,而且会使沉降阶段发育的裂缝发生扩展,裂缝的发育深度一般会变浅。4沾化凹陷古近系-新近系油气运移驱动力最大区主要位于渤南-孤北、桩西和孤南一带,主要受控于主力烃源岩层的沉降幅度和地层温度。孔隙性砂、泥岩在平行层面方向上的渗透率一般大于在垂直层面方向上的渗透率(泥质岩平行层面渗透率与垂直层面渗透率的比值一般在6.62-398.77,均值为220.79；砂岩平行层面渗透率与垂直层面渗透率的比值一般在1.05-7.17,均值为4.72)；裂缝性砂、泥岩的渗透率大于孔隙性砂、泥岩的渗透率(裂缝性泥质岩的渗透率是孔隙性泥质岩渗透率的1.35-21000倍,平均2729.17倍；裂缝性砂岩渗透率是孔隙性砂岩渗透率的1.17-178.57倍,平均29.49倍)。5与裂缝有关的油气藏形成特点表现为油气在烃源岩层最大驱动力作用下,主要沿裂缝发生运移,油气自裂缝进入储层后,油和气受油、气、水的运移阻力差异作用在储层中的饱和度不断增加而聚集,油气藏主要形成于裂缝带,非裂缝带不易形成油气藏。与断裂有关的油气藏形成特点表现为油气在烃源岩层最大驱动力作用下,主要通过断层运移至断层顶端并聚集,最后进入断层顶端相邻的圈闭和储层中成藏。这一过程中,油气的运移主要与断层的走向有密切关系,若断层顶端为倾伏状,油藏主要分布在断层上倾端,若断层顶端为水平状,油气藏则沿断层顶端走向分布。6在沾化凹陷,与裂缝有关的油气藏勘探中,平面上应以超过埋深2000m的范围为有利含油气区,垂向上以烃源岩为底界,从源岩层向浅层进行勘探,烃源岩层内和邻近烃源岩层的砂体和泥岩裂缝带为有利含油气勘探部位。与断层有关的油气藏勘探中,对于断层顶端倾伏的断层,断层顶端附近的储层和圈闭为有利含油气区,对于断层顶端水平的断层,沿断层顶端走向两侧的储层和圈闭为有利含油气区。更多还原

【Abstract】 The differnence of Subsidence and Uplift in the petroltferous basin and their relationship with faults and fractures greatly influence on the formation of the oil and gas reservoir. At the present time, the research on it is scarce.In the paper, based on the analysis of deposition-subsidence features of the middle and upper part of the3rd member,the upper and lower part of the2nd member, the1st member of Shahejie formation, Dongying formation,Guantao formation,Minghuazheng formation and the Quaternary, and of the erosion feature of Dongying formation in Zhanhua depression, the differences in subsidence and uplift of the major hydrocarbon source rocks of Zhanhua depression (the upper part of the4thmember-the middle part of the3rd member of Shahejie formation) in the sedimentary period of the upper part of the3rd member,the upper and lower part of the2nd member, the1st member of Shahejie formation, Dongying formation,Guantao formation,Minghuazheng formation and the Quaternary were researched. The relation between the fault and the differences in subsidence is researched through the research of seismic datas, The relation between the development characteristics of crack and the differences in subsidence is analyzed through the observation of crack in the core of the Paleogene-Neogene in Zhanhua depression and the compression-elasticity-fracture experiments of rock. The difference of transport capability between the different transport mediums is compared on the basis of the the experimental results of permeability of porous and fractured rock. Based on the above research, combination with the analysis of the driving force for hydrocarbon migration, the forming characteristics of oil and gas reservoir related to fault and crack of the Paleogene-Neogene in Zhanhua depression are discussed.The main conclusion as follows:1. The subsidence center of the major hydrocarbon source rock mainly distributed near Bonan-Gubei and Fulin-Gunan areas in the sedimentary period of the upper part of the3rd member of Shahejie formation to the sedimentary period of, the1st member of Shahejie formation, the subsidence center mainly distributed near Bonan-Gubei,Zhuangxi and Gunan areas in the sedimentary period of Dongying formation to Quaternary. In the sedimentary period of the1st member of Shahejie formation the largest degree of subsidence was more than1200m; In the sedimentary period of Dongying formation, it was more than1800m in Bonan-Gubei and Gunan areas, than1300m in the Zhuangxiarea; It was more than2000m in the sedimentary period of Guantao formation and3400m in the Quaternary(the major hydrocarbon source rocks began to generate more oil and gas in the period). On the whole, the mainly distributed areas of the largest degree of subsidence were steady in the sedimentary period of the upper part of the3rd member of Shahejie formation to the sedimentary period of the1st member of Shahejie formation, but from the sedimentary period of Dongying formation to Quaternary, it migrated step by step to the southeast, the subsidence degree of the depression reduced greatly from the subsidence center to the northwest. The present area of the largest structural depth of the major hydrocarbon source rock were located in Bonan-Gubei, Zhuangxi and Gunan, and developed from the subsidence of the sedimentary period of the middle part of the3rd member of Shahejie formation.2. The fault could be divided into two types based on the relation between the fault and the area of the largest structural depth. Along the fault strike, the first type is that the fault dug in the area of the largest structural depth or intersected the structural contour, the second type that the fault did not dig in the area of the largest structural depth and approximately paralleled the structural contour.3The burial process of stratum could divided into three phase:compaction phase, elastic-plastic compression phase, fracturing phase. In the Paleogene-Neogene formations of Zhanhua depression, there are parallel crack, vertical crack and oblique crack in sandstones and mudstones, some parallel cracks have the slipped features that greatly existed in mudstones. The main kinds of crack complex are "gong" or "T". In Zhanhua depression the crack developed in the mud rock which burial depth is more than2000m. In the development of Zhanhua depression, the different extension capability between zhe different rocks in the parallel direction is the mainly reason for the formation of parallel crack. With the increase of the pressure caused by the overlying rock, vertical crack would occur in the rock due to the restriction of the extension capability of rock in the horizontal direction. When the vertical pressure is unbalanced, the oblique crack would easily occur in the rock. When the uplift occurs in the basin, it would induce the development of the crack in the rock, lead the crack developed in the period of subsidence of the basin to expand, and cause he burial depth of the rock which the crack developed in to shallow4The area of the largest driving force for hydrocarbon migration in the main hydrocarbon source rock are distributed near Bonan-Gubei,Zhuangxi and Gunan, controlled by the subsidence degree and formation temperature of the main hydrocarbon source rock and corresponded with the area of the largest burial depth of the main hydrocarbon source rock in the key geologic period. The driving force for hydrocarbon migration greatly reduced from the area of the largest driving force to the around. In the porous rock, the parallel permeability is greater than the vertical (Parallel permeability is6.62-398.77times of vertical permeability in mudstone, average220.79times; parallel permeability of sandstone is1.05-7.17times of vertical permeability, average4.72times). The permeability of fractured rock is greater than the permeability of porous rock(Fractured mudstone permeability is1.35-21000times of porous mudstone, average2729.17times; fractured sandstone permeability is1.17-178.57times of porous sandstone, average29.49times.). The pathway system of hydrocarbon of the Paleogene-Neogene in Zhanhua depression was divided into two types. One type is related to the crack and mainly constituted of porous and fractured rock, and could be divided into the non-fracture developing belt and the fracture developing belt on the basis of the2000m of burial depth. Another type is related to the fault. and mainly constituted of all kinds of faults, according to the burial depth feature of the fault top along the strike of fault, this type could be divided into the plunging fault and the horizontal fault pathway system of hydrocarbon.5. In the Zhanhua depression, the forming process of oil and gas reservoir related to crack, as the action of the largest driving force in the hydrocarbon source rock, oil and gas mainly migrates along the crack, and finally entrances into the trap. According the migration resistance difference between oil, gas and water, the oil and gas reservoir would form with the increase of saturation of oil and gas in the reservoir and. The oil and gas reservoir related to the crack is mainly distributed in the developing crack belt, it is hard to form the oil and gas reservoir in the non-developing crack belt. In the forming process of oil and gas reservoir related to fault, oil and gas migrates along the fault, buoyancy-driven hydrocarbon easily float up to the top of the fault, assembles the top of the fault, and finally gathered in the adjacent traps and reservoir. The oil and gas reservoir distribution is related to the burial depth feature of the fault top along the strike of fault. If the fault top is plunging, the oil and gas reservoir is mainly distributed in the trap and reservoir adjacent to the fault peak; if the fault top is horizontal, the oil and gas reservoir is mainly distributed in the trap and reservoir adjacent to the fault along the strike of fault.6. In Zhanhua depression, in the process of the exploration of oil and gas reservoirs related to the crack, the favorable oil and gas distribution on the plane is mainly located in the range that the burial depth of the hydrocarbon source rock is more than2000m, in the vertical, the oil and gas exploration should start from the main source rocks for the bottom line, from deep to shallow, the attention should be paid to the sandbody located in or adjacent to the source rocks and the crack belt of madstone. in the process of the exploration of oil and gas reservoirs related to the fault, for the fault which top is plunging, the favorable oil and gas distribution is mainly located in the area of the fault peak; for the fault which top is horizontal, the favorable oil and gas distribution is mainly located in the both sides of the fault along the strike of fault.更多还原