一种独特的隐蔽油藏--夏9井区成岩圈闭油藏成因分析及其对勘探的启迪  

A type of specific subtle reservoir:Analysis on the origin of diagenetic trapped reservoirs and its significance for exploration in Xia 9 wellblock of Junggar Basin

作　　者：旷红伟[1] 高振中[2] 王正允[2] 王晓光[1] 

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室 [2]长江大学

出　　处：《岩性油气藏》2008年第1期8-14,共7页Lithologic Reservoirs

摘　　要：夏9井区系在一向北东方向抬起消失的鼻状构造背景上,既无构造圈闭,亦无砂层上倾尖灭圈闭,在该鼻状构造的低部位,于三叠系、侏罗系内发现了多个规模不一的油藏;对于同一砂层,构造低部位为油层,而构造高部位却均为水层,如此"低油高水"的反常现象,一直困扰着石油地质工作者。近年,笔者从实际资料入手,通过深入研究后认为:成岩遮挡是夏9井区油藏的主控因素;而构造坡度变缓带则是形成成岩遮挡的必要条件。成岩遮挡强度与储层物性条件密切相关:物性条件好者,其成岩遮挡强度较低,只能形成规模较小的油藏;物性甚好者,其成岩遮挡强度甚差,不能封堵住油气,则不能成藏;相反,物性条件稍差者,其成岩遮挡强度较高,则可形成规模较大的油藏。可见,此类成岩圈闭油藏的成藏规模与储层物性的优劣呈负相关关系。夏9井区成岩圈闭油藏的发现及对其成因的认识,为隐蔽油气藏提供了一个新的勘探目标。The geological setting of Xia 9 wellblock is a nose structure which uplifted and disappeared toward northeast direction with no structural trap and up dip wedge out trap. Several different scale reservoirs were discovered in the lower part of this nose structure in the Triassic and Jurassic strata. To a same sand body, the lower part of the structure is oil layer; however, the higher part of the structure is water layer. This abnormal phenomenon has been an enigma for a long time. Recently, based on the actual data and research, it is considered that diagenetic shading is the key factor in essential con controlling the distribution of the reservoirs in Xia 9 wellblock, and that the structural break slope is an dition for the forming of diagenetic shading. The intensity of diagenetic shading is closely related to physical properties of reservoir. The accumulation scale of this diagenetic trapped reservoir is inversely correlated with the physical properties. The discovery and the understanding of the diagenetic trapped reservoirs in Xia 9 wellblock provide a new target for oil and gas exploration.

关 键 词：成岩遮挡 成岩圈闭油藏 夏9井区 准噶尔盆地 

分 类 号：P618.130.1[天文地球—矿床学]