苏里格气田东区下古生界马五5段储层有利区预测

Prediction of favorable districts of M55 Member in Lower Ordovician of Eastern Sulige gas field

近几年开发实践表明：奥陶系马家沟组马五；段储层具有试气无阻流量高、产气能力强的特征，但与此同时也面临着一些问题，如储层横向变化快、发育规模小、展布规律不明确等，给储层预测和井位部署带来很大挑战，导致该储层气层钻遇率较低。针对这种情况，首先从区域背景认识着手，研究沉积相与储层发育关系，认为东区马五；储层不具备广泛发育白云岩的沉积环境，而局部发育的云坪相、颗粒滩相才是要寻找的开发目标．这也是导致储层钻遇率较低原因：其次，进一步深化白云岩形成机理认识．首次提出利用“古地形对应原理”预测马五；白云岩储层展布；然后，深入分析马五。气藏成藏模式和主控因素，认为马五；成藏具有侧向和垂向双重运聚模式，从区域上看．“区域剥蚀带”相对“沟槽侵蚀区”成藏更为有利．而古地貌相对较高部位的古斜坡单元是马五；储层开发有利区。、研究成果具有广泛的应用前景，它在区域上指明了马五。气藏开发有利目标．提供了马五。白云岩展布可操控性预测的方法．对邻区下一步油气勘探及开发具有重要参考价值.

The development practice in recent years shows that the reservoirs of Ma5 5 Member in the Ordovician Majiagou Formation has characteristics of high open flow capacity when testing for gas, and a strong gas producing capacity. Meanwhile there are several problems encountered, such as rapidly lateral variation of reservoirs, small development scale, and unclear reservoir distribution. This brings a great challenge to reservoir prediction and well location selection, resulting in low probability of penetration into gas reservoirs. In view of this situation, first of all, proceeding from the regional background understanding, through study of the relationship between the sedimentary facies and reservoir development, it＇ s considered that the Ma5 5 reservoirs do not have a depositional environment in which the dolomitite widely developed. While locally developed dolomite- flat facies and granular- beach taeies are actually the development targets to look for. This is one of the reasons leading to low probability of penetration of the reservoirs. Secondly, it＇ s first proposed that the distribution of the dolomite Ma5 5 reservoirs is predicted by application of a ＂paleo-topographic correspondence principle＂ through further deepening the understanding of the fornmtion mechanism of dolomite. Afterwards, through in-depth analysis of the SRCA pattern and main controlling factors of Ma5 5 gas reservoirs, it＇ s considered that the SRCA is with dual migration and accumulation patterns of lateral and vertical orientations. From a regional point of view, ＂ regional denudation belts＂ are more favorable for the SRCA than the ＂trench erosion zones＂. The ancient slope units in the relatively high paleo-topographic parts are favorahle areas for development of M5 5 reservoirs. The research results have broad application prospects. They point out regionally the favorable targets for development of M5 5 gas reservoirs, and provide manageable methods of forecasting the distribution of dolomite M5 5 reservoirs. It maybe has important reference value for the next oil/gas exploration and development in adjacent areas.