doi:10.16186/j.cnki.1673-9787.2020050071

Received:2020/05/22

Revised:2020/06/29

Published:2022/01/10

Ｒeasons for low productivity of the dense sandstone gas reservoir in the 8th Member of the Shihezi Formation in the Linxing Block，eastern Erdos Basin

XU Yanyong , HAN Xu , ZHANG Bing , LU Xiaoxia

China United Coalbed Methane Co. ，Ltd. ， Beijing 100011 ， China

Abstract: In order to uncover the reasons why dense sandstone gas reservoir sometimes has low productivity and to put out pertinent exploitation strategies，the 8th Member of the upper Paleozoic Lower Shihezi Formation in the Linxing Block，eastern Erdos Basin was studied herein． The characteristics of the focused low-productivity gas reservoir had been described on the basis of casting thin sections，mercury injection，physical properties， and sensitivity analyses． The results showed that the 8th Member of the Shihezi Formation was mainly composed of lithoclastic quartz sandstones，with high proportion of plastic components and clay minerals． The reservoir exhibited typical low porosity，low permeability，high displacement and median pressure，low mercury removal efficiency，and strong inhomogeneity features． These geological and physical conditions tended to make the dense sandstones become medium-strong velocity sensitivity，strong water sensitivity，and medium-weak stress sensitivity，ultimately bringing about low production of gas wells in this area． Effective engineering strategies to re lease the productive capacity of the 8th member of the Shihezi Formation were suggested to be strengthening the protection on the reservoir during drilling process，selecting suitable fracturing fluid formula，controlling fracturing flowback time，and scientifically managing gassing and production test.

Key words:Erdos Basin;Shihezi Formation;dense sandstone gas reservoir;low productivity

 鄂尔多斯盆地东缘临兴区块盒8段致密砂岩储层天然气低产原因剖析_徐延勇.pdf