三肇地区致密油成藏主控因素与成藏模式

针对三肇地区不同构造单元致密油藏特征及规模存在差异的问题,通过对致密油成藏条件、成藏期剩余压力、断裂分布、砂体展布和物性特征等进行分析,建立各构造单元扶余油层致密油成藏模式.研究结果表明:明水组末期致密油充注成藏的主要动力为烃源岩大规模成熟时生烃增压所形成的剩余压力;断裂+砂体构成的立体输导体作为侧向运移的重要通道,是...

Main Controlling Factors and Modes of Tight Oil Accumulation in Sanzhao Area

In view of the differences in the characteristics and scale of tight oil reservoirs in different tectonic units in Sanzhao area, tight oil accumulation mode of Fuyu oil-bearing formation in each tectonic unit was established by analysis of tight oil accumulation conditions, residual pressure in the accumulation period, fault distribution, sand distribution and physical property characteristics. The results showed that the main driving force of tight oil charging and accumulation in the late period of the Mingshui Formation was the residual pressure formed by hydrocarbon generation and pressurization when the hydrocarbon source rocks matured on a large scale; as an important channel of lateral migration, the three-dimensional conductor composed of fault and sand was a necessary condition for the formation of quasi continuous hydrocarbon accumulation; the local “sweet spot” reservoir under the background of tight oil was a favorable area for tight oil enrichment and high production. Three accumulation modes were established: “overpressure driving and near-source oil and gas backflow” in the northern sedimentary center of the sag, “fault-sand matching and near-source lateral migration and accumulation” in the peripheral slope area, and “fault transmission and distant-source lateral migration and accumulation” in the southern uplift. Accumulation modes and tight oil enrichment rules were different in different regions. This study may provide a geological basis for the selection of tight oil exploration targets in different regions.