渤海湾盆地东营凹陷古近系碎屑岩储层成岩研究

RESERVOIR DIAGENETIC SEQUENCE AND ITS INFLUENCE ON PORE DEVELOPMENT IN THE PALEOGENE SANDSTONES IN THE DONGYING SAG OF THE BOHAI BAY BASIN

应用大量的钻井取心分析测试、薄片、X-衍射等资料,对渤海湾盆地东营凹陷古近系碎屑岩储层成岩序列和孔隙演化进行了研究。东营凹陷古近系埋深大于3000 m的碎屑岩储层可划分为晚成岩A,B,C 3期;储层孔隙演化的影响因素包括原始沉积作用、成岩作用、生物扰动和构造作用,其中沉积物性质、温压条件、水介质性质和流动方式又在一定程度上影响了成岩作用的强度。从晚成岩A期到晚成岩C期,有机质成熟过程、粘土矿物转化、烃类与硫酸盐矿物的热化学氧化还原反应等造成的酸性地层水介质,使东营凹陷古近系碎屑岩储层在不同构造部位分别发育3个次生孔隙发育带。这一结论对该区的油气勘探具有指导作用。

Based on the data of drilling;, coring, microscopic analysis and XRD, the diagenetic sequence and secondary pore development of the Paleogene sandstone reservoirs in the Dongying Sag were stu died. It was considered that the Paleogene sandstone reservoirs were buried more than 3 000 m and were at the stage of late diagenesis A, Bar, d C. The influence factors of reservoir pores mainly included primary deposition, diagenesis, bioturbation and structural condition, in which sediments characters, temperature, pressure and fluid could affect the diagenesis strength to some extent. Three secondary pores zones were developed in Dongying sag as a result of actions of acid formation liquid caused by the organic mailer maturation, clay minerals transformation and thermochemical redox reactions of hydrocarbon and sulfate minerals in the Paleogene sandstones in different tectonic block from late diagenesis A stage to late diagenesis C stage.