【作者】 连承波；

【导师】 钟建华； 崔宝文；

【作者基本信息】 中国石油大学 ， 矿物学、岩石学、矿床学， 2009， 博士

【摘要】 随着油气勘探程度的不断加深,以及以中、高渗透率为主的老油田逐渐进入中高含水期开采,低渗油藏的重要性日益明显。本文围绕松辽盆地龙西地区泉四段低渗透储层特征及油气富集规律这一主题,综合利用地震、测井、岩心和分析测试等资料,运用多学科理论和方法技术对其相关内容进行了系统的研究。在松辽盆地龙西地区泉四段构造、沉积、成岩研究的基础上,对泉四段低渗透砂岩储层物性特征及其影响因素进行了系统的分析。研究表明,龙西地区泉四段砂岩成份和结构成熟度较低,储层物性呈现明显的低孔低渗特征,孔隙类型以缩小粒间孔和溶蚀孔为主,孔喉半径较小,相对较小孔喉半径所占比率大,孔喉分选和连通性较差,非均质性强。泉四段砂岩颗粒成成份成熟度低,岩石的抗压性弱,压实作用强,低成份成熟度是导致储层物性差的重要原因;钾长石的溶蚀作用是泉四段储层物性改善的主要因素。储层物性与粒度大小和均匀程度的好坏呈正相关,泉四段砂岩粒度较细,均匀程度较差是形成低孔低渗储层的内在因素之一。填隙物影响孔隙空间被充填的程度和孔隙结构的复杂程度,较高含量填隙物是造成储层物性较差的原因之一。压实作用和胶结作用使得原生孔隙减小,物性变差,而溶蚀作用使得储层物性得到改善。构造主要通过对储层埋深和流体性质的影响,改变成岩作用环境,进而对储层物性产生影响。通过对松辽盆地龙西地区泉四段油气成藏主控因素分析,认为青一段烃源岩生成的油气,主要通过两种方式运移到泉四段储层:一种是在青一段泥岩由压实和生烃作用形成超压作用及伴随着构造活动泉四段断层产生扩容空间的负压空吸作用下,形成较大的源储压差,生成的油气沿着高角度断层向下运移到泉四段储层;另一种是在青一段烃源岩沿上倾方向直接和泉四段储层侧向对接的条件下,青一段生成的油气通过侧向运移到泉四段储层。敖古拉-哈拉海断裂带活动导致的差异升降,断裂带以西地区形成明显的向斜区域,油气难以在此运移聚集成藏,而在断裂带以东为斜坡带,有利于油气的侧向运移,断裂西侧的下降导致青山口组的泥岩和泉四段砂岩对接,形成侧向封堵,这种条件下有利于在敖古拉-哈拉海断裂带以东形成大面积的断层岩性油藏。更多还原

【Abstract】 The low permeability reservoirs is becoming more and more important, as well as the mid-high permeability old fields entered mid-high water cut stage with the development of oil gas exploration. In this paper, the research centering on low permeability reservoir characteristics and hydrocarbon accumulation in Longxi area is made, based on comprehensive utilization of seismic, well logging, coring and analysis of testing data and multi-disciplinary theoretical and methodological techniques.On the basis research on characteristics of structure, deposition and diagenesis, low permeability sandstone reservoir characteristics and influencing factors of Quan4 Formation in Longxi area of Songliao basin are systematically studied. Sandstone composition and structure maturity are lower with obvious characteristics of low porosity and low permeability. The pore spaces are completely dominated by the residual intergrannular and intragrannular solution pores. The heterogeneity of pore structure is intense, and the pore throats are fine. Due to the lower composition maturity, compressive strength is weak, and compaction is strong. The low composition maturity are mainly responsible for poor reservoir properties. Dissolution of K-feldspar contributed a large amount of secondary porosity, is an important effective factor. The relation between reservoir properties and particle size is positive. Reservoir properties and particle uniform level is a positive correlation. Fine particle and poor uniformity of Quan4 Formation sandstone are the internal factors of low porosity and low permeability. The interstitial material fills the pore space, and makes pore structure complicate.The high content of interstitial material is one of the reasons of poor reservoir properties. Compaction and cementation makes primary porosity decreased, and the physical properties deteriorate.Dissolution improves the reservoir properties. Structure changes in environment of diagenesis mainly through the depth and fluid nature of the reservoir, and has an impact on reservoir properties. Base on main factors controlling on hydrocarbon pooling of Quan4 Formation in Longxi area of Songliao basin, oil and gas generated from hydrocarbon source rock of Qing1 formation mainly migrate into Quan4 Formation in two ways. one is oil and gas generated from hydrocarbon source rock of Qing1 formation migrate down along the faults into Quan4 Formation under the large below -souce pressure difference. The large below-souce pressure difference is up to abnormal pressure of Qing1 formation formed by compaction and hydrocarbon generation and negative pressure of Quan4 Formation generated along with fault activity. The other one is oil and gas generated from hydrocarbon source rock of Qing1 formation lateral migrate into Quan4 formation under the conditions of hydrocarbon source rock of Qing1 formation on the dumping direction lateral connection to Quan4 Formation formed by fault activity. The activity of Aogula-HaJahai faulted zone formed the regional syncline in its west, where is not conducive to migration and accumulation of oil and gas. The eastern area of Aogula-HaJahai faulted zone is slope, where is conductive to lateral migration of oil and gas. The activity of Aogula-HaJahai faulted zone formed the mudstone of Qingshankou lateral connection to the sanstone of Quan4 formation on the dumping direction in the west side of Aogula-HaJahai faulted zone, where is conducive to accumulation of oil and gas. A large number of fault-lithologic oil and gas pools formed in the eastern area of Aogula-HaJahai faulted zone.更多还原