准噶尔盆地腹部深层储层物性保存过程多因素耦合分析

准噶尔盆地腹部莫索湾地区深层三工河组储层主体埋深在3 800~4 600 m之间，但储层物性条件相对优越，是盆地腹部油气勘探和发现的重点层位之一，因此明确其优质储层物性保存多因素耦合关系及成因机理对后期油气勘探开发具有重要意义。通过岩石薄片、扫描电镜、物性、黏土矿物X衍射等分析测试及钻测井资料，在物性保存单因素分析基础上，结合地层埋藏史及区域构造演化，从多因素间演化匹配关系出发详细讨论了莫索湾地区三工河组深层优质储层的物性保存过程。结果表明:优势沉积条件、地层超压、成岩流体碱性到酸性的转变、较低的古地温，4类单因素分别使储层物性得以有效保存。而储层物性保存过程最终可划分为5个演化阶段，且在不同演化阶段物性保存的主控因素也不同。缓慢浅埋期主控因素为浅埋深和地层超压的初始形成；第一次快速深埋早-中期为地层超压；第一次快速深埋晚期至缓慢深埋早-中期由超压转变为胶结物的固结；缓慢深埋中-后期为低地温梯度及有机酸的溶蚀；第二次快速深埋-现今为超压及地温梯度的降低，并最终建立三工河组综合成岩及油气聚集模式。

Multi-factor Coupling Analysis on Property Preservation Process of Deep Buried Favorable Reservoir in Hinterland of Junggar Basin

Although buried in depth between 3 800~4 600 m, reservoirs of Sangonghe Formation in Mosuowan area have a relatively favorable physical properties, and become one of the key formations in hydrocarbon discoveries in hinterland of Junggar Basin.Thus, for later oil-gas exploration and development, it is of great significance to make clear multi-factor relationships and genetic mechanism of favorable reservoirs which are deeply buried.Through microscopic thin section, scanning electron microscope analysis, physical property analysis, X-ray diffraction of clay mineral, and well drilling-logging data, together with burial history, tectonic evolution, and based on single factors analysis of reservoir property preservation, present paper carries out a detailed multi-factor coupling analysis and discussion in property preservation process of deep buried clastic reservoir of Sangonghe Formation.The results demonstrate that favorable depositional conditions, strata overpressure, changes of diagenetic fluid properties and paleogeotemperature, these four factors respectively make the reservoir properties effectively preserved.Furthermore, the process of property preservation process can be divided into 5 stages, and during different evolution period, the main controlling factor of property preservation is different.During the slow shallow burial period, the main controlling factor were shallow depth and the beginning of strata overpressure;early to mid stage of first quick deep burial period the main factor was strata overpressure;mid to late stage of first quick deep burial and early to mid stage of slow deep burial period the main factor changed from strata overpressure to consolidation of cements;mid to late stage of slow deep burial period the main factor were low geothermal gradient and the dissolution of organic acid;while the second quick deep burial period to nowadays, the main factor are strata overpressure and decrease of geothermal gradient, and finally an oil-gas accumulation and comprehensive diagenetic evolution model of Sanggonghe Formation is proposed.