综合物探技术在河套盆地深层油气勘探中的先导性应用:以临河坳陷为例

Application of Comprehensive Geophysical Prospecting Technology in Deep Oil and Gas Exploration in Hetao Basin: Taking Linhe Depression as an Example

河套盆地勘探程度低,有利勘探层系埋藏深,40余年未获突破,为实现河套盆地油气勘探快速突破,整体开展了高精度重磁和时频电磁勘探工作.针对盆地主力生烃区不清、构造难以厘定的问题,应用基于有限井震资料松约束多界面反演、基底背景密度法正演剥层为核心的深层目标重力异常提取技术,对临河坳陷的地质结构重新进行了认识,快速圈定了主力生烃凹陷分布,指出坳陷北部巴彦淖尔凹陷的淖西深洼槽为最有利的生烃区,新发现黄河断陷槽及淖西深洼槽周缘分布的中央兴隆断垒式潜山披覆构造带、吉西凸起东翼鼻状潜山披覆构造带等近源油气有利勘探目标,引导了地震针对性快速高效部署和钻探.针对成藏目标不清、突破井位难以落实的问题,提出并应用了基于井震模拟目标层靶向采集、电磁井震联合约束反演等提高深层勘探分辨率及油气储层预测精度的时频电磁勘探配套技术,快速锁定了JHZK2井、吉华2x及临华1x等有利目标靶区,为河套盆地油气勘探高效突破发挥了关键先导性作用,为类似复杂区特别是盆地深层油气勘探提供了成功范例与技术方法 .

The Hetao Basin has a low degree of exploration and the favorable exploration strata are deeply buried. No breakthroughs have been achieved in more than 40 years. In order to achieve rapid breakthroughs in oil and gas exploration in Hetao Basin, high-precision gravity and time-frequency electromagnetic exploration have been carried out as a whole. Aiming at the problems that the main hydrocarbon-generating areas in the basin are unclear and the structure is difficult to determine,a new technology for deep target gravity anomaly extraction based on loose constrained multi-interface inversion based on finite well and seismic data and gravity forward stripping based on basement background density methodis applied. After these work, the geological structure of Linhe depression is re-recognized and the distribution of main hydrocarbon generating sags is quickly confirmed. It’s pointed out that the Naoxi deep sub-sag of Bayannur sag in the north of the depression is the most favorable hydrocarbon generating area. The newly discovered favorable exploration targets for near source oil and gas, such as the central Xinglong faulted horst type buried hill drape structural belt and the nose shaped buried hill drape structural belt on the east wing of Jixi high, which are distributed around the Yellow River fault sub-sag and Naoxi deep sub-sag have led to targeted, rapid and efficient seismic deployment and drilling. Aiming at the problems of unclear reservoir target and difficult determination of breakthrough well location, time-frequency electromagnetic exploration supporting technologies such as target layer targeted acquisition based on well seismic simulation, electric-magnetic-well-seismic joint constrained inversion to improve the resolution of deep exploration and the prediction accuracy of oil and gas reservoirs have been proposed and applied. The resolution of deep exploration and the prediction accuracy of oil and gas reservoirs are improved. Favorable target areas such as well JHZK2, well Jihua 2x and well Linhua 1x are quickly locked. It has played a key leading role in the efficient breakthrough of oil and gas exploration in Hetao Basin and has provided successful examples and technical methods for deep oil and gas exploration in similar complex areas and special basins.