柴达木盆地英雄岭构造带新近系碎屑岩发育特征及油气勘探方向  

Development characteristics and exploration targets of Neogene clastic rocks in the Yingxiongling structural belt, Qaidam Basin

作　　者：王艳清 刘占国 杨少勇[2] 魏学斌[2] 李森明 吴颜雄[2] Wang Yanqing;Liu Zhanguo;Yang Shaoyong;Wei Xuebin;Li Senming;Wu Yanxiong(PetroChina Hangzhou Research Institute of Geology;PetroChina Qinghai Oilfield Company)

机构地区：[1]中国石油杭州地质研究院 [2]中国石油青海油田公司

出　　处：《中国石油勘探》2019年第1期60-71,共12页China Petroleum Exploration

基　　金：国家科技重大专项"岩性地层油气藏成藏规律;关键技术及目标评价"(2017ZX05001-002);"致密油富集规律与勘探开发关键技术"(2016ZX05046-006);中国石油天然气股份有限公司重大科技专项"柴达木盆地建设高原大油气田勘探开发关键技术研究与应用"(2016E-01)

摘　　要：英雄岭构造带位于柴达木盆地西部地区,先后发现了狮子沟、花土沟、油砂山、英东等多个新近系油气田,是柴达木盆地石油勘探的主战场。为了拓展英雄岭构造带新近系碎屑岩岩性油气藏勘探领域,通过野外露头、钻井岩心、粒度测试等资料的综合分析,明确新近系碎屑岩发育滨浅湖滩坝、辫状河三角洲水下分流河道两种类型砂体。在湖退沉积背景下,受西部物源控制的辫状河三角洲水下分流河道砂体逐步向湖盆进积,北西—南东向斜列式分布的滨浅湖滩坝砂体向湖盆迁移;上干柴沟组辫状河三角洲水下分流道砂体发育在构造带以西地区,滩坝砂体发育在构造带西翼及核部;下油砂山组辫状河三角洲水下分流河道砂体发育在构造带西翼及核部,滩坝砂体分布在构造带核部及东翼。构造演化特征表明,新近系上干柴沟组、下油砂山组沉积时期储层砂体分布在斜坡区,而现今的英雄岭构造带为新近系狮子沟组沉积末期形成的晚期反转构造,早期沉积的砂体在构造反转背景下可形成上倾尖灭岩性圈闭、砂岩透镜体岩性圈闭,是寻找规模岩性油藏的有利勘探目标区。Located in the western part of the Qaidam Basin, the Yingxiongling structural belt developed many Neogene oil and gas fields such as Shizigou, Huatugou, Youshashan and Yingdong, and so becomes the primary battlefield for oil exploration in the Qaidam Basin. In order to expand the exploration field of Neogene clastic lithologic reservoirs, comprehensive analysis has been carried out on outcrops, cores,particle size test and other data, and based on which two types of sandstones in shallow lake beach and underwater braided river delta were identified. On the background of lacustrine sedimentation, underwater braided river delta sandstone gradually accumulated into the lake basin under the control of western sources, and the NW-SE echelon-like shallow shoal lake beach sandstone migrated into the lake basin. The upper Ganchaigou underwater braided river delta sandstone is developed in the west of the structural belt, and the beach dam sandstone is developed in the west wing and the core of the structural belt. The lower Youshashan underwater braided river delta sandstone is developed in the west wing and the core of the structural belt, and the beach dam sandstone is developed in the east wing and the core of the structural belt. The structural evolution features indicate that the Neogene sandstone reservoirs in the upper Ganchaigou Formation and the lower Youshashan Formation were distributed in the slope area when they deposited, but today’s Yingxiongling structural belt is the late inverse structure formed at the end of the Neogene Shizigou Formation. The sandstone deposited in the early stage might form lithologic traps like updipped pinchout and sandstone lens on the background of tectonic inversion. They are favorable exploration targets for finding large-scale lithologic reservoirs.

关 键 词：柴达木盆地 英雄岭构造带 新近系 碎屑岩 油气勘探 

分 类 号：TE111.3[石油与天然气工程—油气勘探]