苏里格东南区古地貌恢复及其与气水分布关系

(1.低渗透油气田勘探开发国家工程实验室,陕西 西安 710018; 2.中国石油长庆油田公司 勘探开发研究院,陕西 西安 710018; 3.西北大学 大陆动力学国家重点实验室,陕西 西安 710069)

苏里格东南部; 古地貌恢复; 印模法; 残厚法; 气水分布特征

Palaeogeomorphologic restoration and relation to the distribution of gas and water in the southeast of Sulige Area
ZHANG Chen1,2,LI Jin-bu1,2,CHEN Cun-Liang1,2,LIU Zhi-heng1,2,ZHANG Yuan-yuan3,REN Zhan-li3,YANG Yan3

(1.National Engineering Laboratory for Exploration and Development of Low-Permeability Oil & Gas Fields,Xi'an 710018,China; 2.Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi'an 710018,China; 3.State Key Laboratory for Continental Dynamics,Northwest University,Xi'an 710069,China)

southeastern part of Sulige Area; impression method; residual thickness method; characteristics of gas and water distribution

DOI: 10.13800/j.cnki.xakjdxxb.2019.0316

备注

综合运用沉积古地质分析法、印模法、残厚法等,对鄂尔多斯盆地苏里格东南区前石炭纪岩溶微地貌特征进行研究,并结合实际生产数据对其气水分布特征进行总结,发现研究区奥陶纪末岩溶古地貌形态表现为“西高东低、北高南低”的分布格局,发育2类二级古地貌单元和9类三级古地貌单元,其中岩溶斜坡为主体地貌单元,主要发育上斜坡、下斜坡、一级残丘和二级残丘,局部发育古洼地和古沟槽; 研究区马家沟组上组合气水分布主要表现为西北部、东部及东南部地区富气,中西部地区富水的特征。结果 表明:综合以本溪组顶部8#煤层为上基准面的石炭系印膜厚度、以K3标志层为下基准面的残余厚度及其各自与平均厚度间的相对差值,可对研究区岩溶微地貌进行有效刻画; 古残丘及上斜坡地区是有利天然气富集高产区; 水层、气水同产层因受燕山期地层翘倾影响,多分布于研究区中西部古岩溶上斜坡地区; 古洼地、古沟槽溶蚀淋滤作用较弱,虽不利于天然气富集,但仍有少量低产气井分布。

By the comprehensive use of sedimentary paleogeological analysis,impression method,and residual thickness method,the karst micro-geomorphology of the Pre-Carboniferous area in southeast Sulige,Ordos Basin was studied.Combining with actual production data,the characteristics of gas-water distribution was summarized.The study found that the karst paleogeomorphology at the end of Ordovician in the study area was represented by the distribution pattern of “high in the west and south,low in the east and north”,and developed two types of second-order paleogeomorphic units and nine types of third-order paleogeomorphic units.The karst slope is the main physiognomy unit,which is mainly develop on the upper slope,lower slope,primary monadnock and secondary monadnock.Moreover the ancient depression and groove are developed in the local area.The distribution of gas and water in the Majiagou-formation of study area is mainly characterized by the rich gas in the northwest,east and southeast,and the rich water in the central and western regions.Results show that:The karst microtopography in the study area can effectively depicted,by combing the carboniferous film thickness of the 8# coal seam at the top of Benxi Formation and the residual thickness of the lower datum of K3 marker.The monadnock and upper slope area are favorable natural gas enrichment areas.Water is affected by the tilting of the Yanshan Strata,and is mostly distributed in the central and western regions of the upper karst slopes.The anticorrosive and leaching effects of ancient depressions and ancient trenches are weak,but there are still a few stripper well distributed.