准噶尔盆地盆1井西凹陷东斜坡前哨2井在侏罗系三工河组获高产工业气流,开辟了斜坡区三工河组天然气勘探高效领域.为进一步明确该区三工河组油气藏主控因素和油气富集规律,深化三工河组油气勘探,在已钻探井基础上,综合应用岩心、实验分析和地震等资料,对三工河组油气藏类型、成藏特征和控制因素进行研究.结果表明:东斜坡侏罗系三工河组油气主要来源于盆1井西凹陷二叠系下乌尔禾组烃源岩;该区发育深、中、浅3期断裂,垂向上呈"Y"字型组合,配置关系良好,为油气从深层向浅层侏罗系运移提供了良好的输导条件,海西期大型断裂带控制了侏罗系油气的平面分布;三工河组油气藏类型为构造岩性和岩性型油气藏,受古地貌、沉积相带和断裂等因素共同控制,具有"烃源岩供烃、多期断裂接力输导、古地貌控带、凹槽控砂、断裂—砂体控藏"的成藏特征.

为了解决准噶尔盆地南缘地区低阻油气藏饱和度计算数值不准问题,以玛河气田古近系紫泥泉子组低阻砂岩气藏为例.通过孔渗、岩电、铸体薄片、阳离子交换容量等实验数据,研究分析阳离子交换量、阳离子当量电导、阳离子交换容量、胶结指数、饱和度指数等参数的变化规律,建立适用于低阻砂岩气层含水饱和度计算的变参数的Archie饱和度模型和Wax-man-Smits(W-S)饱和度模型,并进行实例井验证,获得良好效果.研究结果表明:在低阻砂岩气层中,常规的Archie模型适用于胶结指数、饱和度指数较小的纯产气或电阻率较低的水层,但在气水同层中解释效果较差;而通过变参数的Archie与W-S模型计算出的含水饱和度值均满足同一段储层下部含水饱和度大于储层上部的规律特征,其结果数据与岩心分析、气测试结果相吻合.两种饱和度计算新模型对低阻砂岩气藏储层饱和度的解释精度和流体识别的准确度提高方面具有重要指导意义.

准噶尔盆地腹部地区前哨低凸带侏罗系三工河组二段油气显示活跃,勘探程度低,潜力较大,为中深层储层,砂体类型为三角洲前缘水下分流河道砂体.针对该类储层埋藏深、砂体薄、侧向叠置、预测难度大的问题,结合去砂技术储层预测方法,利用逐层去砂实验、模型正演、迭代反演等技术手段进行目标识别,对岩性体边界进行精细刻画,识别出14个岩性圈闭,部署预探井1口,试油获得工业油气流,取得了良好的应用效果.该研究能够有效预测前哨低凸带中深层薄砂岩储层,对其他薄层叠置砂体复杂岩性勘探具有重要意义.

The developmental models of deep-buried and thin reservoir sandbodies of the Cretaceous Qinshuihe Formation reservoir in SMZ Area of the northwestern margin of Junggar Basin can be divided rich-sand,comparative development sand,general development sand,poor-sand and rich-mudstone,accordingly waveform classifications are divided intoⅠ,Ⅱ,Ⅲ,Ⅳ andⅤbased on seismic waveform classification technology and wildcat wells data.The plane distribution of the Qinshuihe Formation deep-buried thin reservoir is predicted effectively,which provides reliable basis for deploying exploratory wells accurately and submitting control reserves opportunely.

Through core analysis, well logging, borehole log and seismic data, the sedimentary facies feature and depositional system of Triassic in Wu-Xia fault belt of Junggar basin is systematically studied. The result shows that four types of sedimentary facies occur in this area, they are alluvial fan, fan delta, sublacustrine fan and lake facies. The Baikouquan formation to Baijiantan formation here experienced arid-wet changing climate in lake transgressive process. Baikouquan formation is characterized by alluvial fan groups of Xiazijie and Baikouquan areas; Upper and Lower Karamay formation by fan delta and shore-lake sediment; Baijiantan formation as a largest lake-transgressional episode dominated by lacustrine fan sediment with small scale fan delta and sublacustrine fan sediments. It is concluded that the fan delta front of Karamay formation is the most favorable sedimentary facies with best reservoir property; the midfan of Baikouquan alluvial fan fitted with the faults and unconformities could also be good prospecting areas for hydrocarbon accumulation.

The Toutunhe formation of Shinan field in hinterland of Junggar basin is dominated by braided fluvial deposits with grey-brown lithic sandstone, brown-red and grey-yellow mudstone, and sand depositional thickness of 7～26 m, being a reservoir of medium-low porosity and low permeability. The reservoir is laterally screened by mud and controlled by oil-water interface at low position of the structure. The study shows that the faults and unconformities are dominant in petroleum migration and accumulation of top Jurassic and Cretaceous. The two-stage unconformities between the Cretaceous and Jurassic and between Toutunhe and Xishanyao formations of Jurassic are major channels for petroleum migration, whereas the local normal faults play roles in connecting the oil sources to the reservoirs.

随着准噶尔盆地油气勘探工作的进一步深化,地震综合研究的目标也逐步深入到复杂构造的精细解释和储层研究的定量化上.本文在石南油气田石南21井区侏罗系头屯河组岩性油藏描述中,利用层序地震学技术,结合钻井资料和合成记录,配合沉积相研究,在区域上对地层进行了对比及小层划分,了解层序的构造演化及沉积演化特征,采用地震相分析研究砂体在地球物理参数及地震波形的几何形态变化特征,利用多种储层反演综合对比分析,减少岩性油藏描述中存在的储层反演多解性和反演结果准确性较差的缺点,滚动式研究,不断深化认识,地震、地质、沉积多学科、多专业紧密结合,探索和总结出了岩性油藏的描述方法.