【作者】 赵振宇；

【导师】 周瑶琪；

【作者基本信息】 中国石油大学 ， 地球化学， 2009， 博士

【摘要】 本文通过录井-测井解释、地震资料分析、岩心精细描述、各种地球化学分析测试等手段,对车西洼陷沙四上亚段油气藏储层进行了综合评价,具体包括八个方面的内容:地层精细对比分析、构造特征研究、沉积微相分析、成岩作用与成岩阶段划分、储层温压场恢复、储层物性测井解释、油层定性解释、储层“四性”关系评价等。同时探讨了沉积微相、成岩作用、异常高压等对储层物性与油层分布的控制作用,并通过储层各参数综合分析,确立了本区油气勘探的有利目标区块,这些对于降低油田开发成本、提高开发效率、实现产量稳定具有重要的理论现实意义。在地层对比中,全区共选择标准井7口,建立区域骨架网连井剖面16条,沙四上亚段共划分为3个砂层组,其中包括18个小层(包括39个单砂体)。根据地层高差、断层断距、断层生长指数等数据综合分析显示,该区断层对沉积具有一定的控制作用,并在沙四段沉积之后,工区南部构造抬升强烈,断层活动主要集中在北部和东部。地应力以张性-张剪性应力为主,从中生界末期至今,地应力发生左旋,角度大约为15度。沉积相类型以三角洲相为主,对储层有利的微相类型主要包括:分流河道、水下分流河道、分流河口坝、远砂坝、席状砂等。古水流方向大体由南至北,砂体纵向(南北向)连续性好于横向(东西向)。整体分析该区为多物源供给,以无棣凸起为主,庆云、义和庄凸起为辅。储层岩石碎屑成分主要包括石英、长石、岩屑,粘土矿物成分主要为高岭石、绿泥石、伊利石、伊蒙混层等。储层孔隙类型包括少量的粒间原生孔隙,多数为铸模孔、粒内溶孔等次生孔隙,以及少量的颗粒破裂缝和成岩收缩裂缝等,整体评价该区孔喉半径小,分选程度低,变异系数大,连通性较差。成岩相类型主要有5种,各成岩相按含油量递减排序为:混合胶结相(含油45%),钙质胶结相、溶蚀相、压裂与裂缝相(共含油30%),粘土胶结相(含油25%)。随着地层深度的增加,成岩作用逐渐增强,由浅至深依次为中成岩A1期——中成岩A2期——中成岩B期,其中不同成岩阶段发育不同的次生孔隙类型,且由浅至深呈规律性发育。流体包裹体均一温度与试油试采数据显示,该区一直处于常温状态,工区北部为异常高压区,南部为常压区。异常高压的主要成因为不均衡压实所致,其次受矿物成岩作用的影响。油井高产能层段对应的地层压力系数在1.1—1.3之间,异常高压对于地层温度的增加、矿物成岩作用的加深、流体包裹体的形成等都具有一定的抑制作用。随着地层深度的增加,储层孔隙度、渗透率整体呈现递减的趋势,但出现了3个异常深度带,经分析认为与成岩作用和异常高压有关。油层孔隙度多为10-20%,渗透率多小于10×10-3um2,储层类型为中-低孔特低渗储层,综合评价属于Ⅳ-Ⅴ级较差储层。全区共解释储集层类型六种,包括油层、油干间互、油水同层、含油水层、水层和干层。全区共解释有效油层厚度累计531.2米,其中主力小层为15、25、26、33、37五个小层。通过储层综合评价认为:最有利的4个区块占油层总量的70%;次有利的4个区块占油层总量的18%;其余较差的6个区块占油层总量的12%。更多还原

【Abstract】 By log data and interpretation, seismologic data analysis, core particular description, kinds of geochemical testing and analysis and so on, this paper comprehensively evaluates oil-gas reservoir of the upper ES4 member in Chexi depression, which includes eight parts, as stratigraphic correlation, structure elucidation, sedimentary microfacies analysis, diagenesis and dividing diagenetic stage, recovering paleotemperature and paleopressure, interpreting porosity and permeability by well log, reviewing reservoir characteristic and type, researching the relationship of lithology, physical property, electrical property and oilness, and look for the favorable place for prospecting and payable area. All of these, that are very useful for decreasing cost of exploitation, increasing efficiency of exploitation, maintaining oil-gas output.In the process of comparing strata, we choice seven type wells, sixteen well tie sections, and dividing three sands groups, eighteen layers and thirty night single sand bodies. According to difference of height on the surface of formation, fault displacement, fault growth index, we considered that the fault activity could control on the sedimentation, and after sedimentation of ES4 member, tectonic uplift is more stronger in the southern, and fault activity is main in the northern and eastern of Chexi depression. In work area, tensile stress is primary and chief, from late Mesozoic to Present, which had laevogyrated fifteen degrees.The primary type of sedimentary facies is delta, including some microfacies, such as distributary channel, underwater distributary channel, distributary mouth bar, distal bar and sand sheet and so on, all of which are favorable for reservoir to explore. In this area, paleocurrent direction is approximate from south to north, and longitudinal continuity of sand bodies is much better than lateral continuity. The main provenance is Wudi horseback, the secondary are Qingyun and Yihezhuang horsebacks.The clastic constituents of reservoir sands are composed of quartz, feldspar and debris, and clay minerals are made up of kaolinite, chlorite, illite and andreattite, and the pores are consisted of three types, as primary pores, secondary pores including moldic pores and intragranular pores, and fractures including disrupted and diagenetic shrinkage fractures, all of which are the smaller half length of pore-throat, the lower degree of sorting and connectivity. There are five kinds of diagenetic facies, which can be sequenced for oil content, as mixed cement facies, calcarinate facies, corrosion facies, compaction and fracture facies, clay cement facies. As deeper, the diagenesis is become to be stronger. From the lower to the deeper, diagenesis is divided into three phases, including middle diagenesis A1 phase, middle diagenesis A2 phase, middle diagenesis B phase.This area is always normal temperature system in all ages, where the north is surpressure and the south is normal pressure. The nonequilibrium compression had mainly brought on surpressure and the diagenesis is secondary to form surpressure. The high yield well can be result of the pressure coefficient from 1.1 to 1.3. The surpressure could restrain increasing strata temperature and diagenesis, fluid inclusions from forming.As the formation deeper, the porosity and permeability are become decreasing, but it has unconventional values in three abnormal zone, where the diagenesis and surpressure affect on the porosity and permeability. In work area, there are six reservoir types, consisting of oil layer, oil-dry interval layer, oil and water layer, oily water layer, water layer and dry layer. We interpret the effective thickness of oil layers is 531.2 meters, which includes five main layers, as 15layer, 25layer, 26layer, 33layer and 37layer.According to comprehensive evaluation, we consider that there are four blocks are the most useful for exploration activity than the others, which are seventy percents in total petroleum resources; there are four secondary blocks in eighteen percents of petroleum resources and six blocks in twelve percents of total resources.更多还原