泌阳凹陷梨树凹区块油气成藏期次与成藏过程

Hydrocarbon Accumulation History and Process in Lishuwa Block,Biyang Depression

梨树凹区块位于泌阳凹陷南部陡坡带东段,是受凹陷扩张后期的反转挤压及不均一抬升作用形成的较为明显的鼻状构造。研究区核桃园组储集层主要为侯庄辫状河三角洲前缘亚相的砂体,属中孔、中渗储集层。油源对比结果表明油气主要来自深凹区同层位烃源岩,且存在较为明显的混源现象。根据包裹体的镜下特征、均一化温度,结合典型钻井的埋藏史、热演化史结果,确定该区主要有两期成藏:廖庄末期为主要成藏期,期间核三上段成熟油气及核二段未熟-低熟油气大规模注入;核一末期小规模油气运移散失,是次要成藏期。

Located in southern steep slope of Biyang Depression, Lishuwa Block is formed by late reversal extrusion of the fracture extensional fault depression at the eastern boundary and then by uneven uplifts of the late sag. The reservoirs in this area are mainly sand bodies of Houzhuang braided river delta front, be- longing to media-porosity and media-permeability reservoir. Oil-source correlation shows that the oil and gas were mainly from the same formation source rocks of the furrow area, where there is obvious mixed source. Based on the microscopic characteristics of the brine inclusions, homogenization temperatures, and combined with typical wells＂ burial history, thermal evolution history, this paper reveals that there are mainly two hydrocarbon accumulation stages. Specifically, the end of Ehl is the minor accumulation period with a small-scale oil and gas migration loss, and the later Liaozhuang stage is the main accumulation stage with mass oil and gas accumulation. During the period, the mature oil ＆ gas of Eh3 and the immature -low mature oil ＆ gas of Eh2 were injected into the upper part of the core.