窄河道致密砂岩气藏采气速度优化——以ZJ气田沙溪庙组气藏为例

Optimization of gas recovery rate of tight sandstone gas reservoir with narrow rivers: a case study of Shaximiao gas reservoir in ZJ gas field

曹廷宽 段永明 李南颖 栗涵洁2

中国石化西南油气分公司勘探开发研究院，四川 成都 610041 中国石化西南油气分公司采气三厂，四川 德阳 618000

Exploration & Production Research Institute, Southwest Oil & Gas Company, SINOPEC, Chengdu 610041, China No.3 Gas Production Plant, Southwest Oil & Gas Company, SINOPEC, Deyang 618000, China

窄河道致密砂岩气藏具有河道砂体薄窄、储层物性差、气井控制储量规模小、压力及产量递减迅速的特点，地质条件及开采规律均与层状致密砂岩气藏存在较大差异，需开展针对性的采气速度优化研究。以ZJ气田沙溪庙组气藏为例，综合考虑河道砂体、测井、储层物性特征参数，将主力河道划分为3种类型；结合气藏工程及经济评价方法对各类河道中气井配产及采气速度进行优化，并分析了造成窄河道致密砂岩气藏采气速度高于层状致密砂岩气藏的原因。结果表明：窄河道致密砂岩气藏中水平井合理配产比为1/6~1/3，最优采气速度为4%~6%；河道砂体窄、动用储量规模小，是造成此类气藏采气速度偏高的主要原因。适度提高采气速度，可有效缩短单井的投资回报期，提高窄河道致密砂岩气藏开发的经济效益。

Since tight sandstone gas reservoir with narrow rivers is characterized by thin and narrow rivers, poor physical properties, small controlling reserves and rapid decline in pressure and rate, the geology and production characteristics of this kind of gas reservoirs are different from multilayered tight sandstone gas reservoirs, and it is necessary to optimize the gas recovery rate of tight sandstone gas reservoir with narrow rivers. Taking the Shaximiao gas reservoir in ZJ gas field as a case, the main rivers are divided into three types by the characteristics of river sand, well logging data and reservoir physical property. Then the gas rate of horizontal wells and recovery rate of rivers are optimized by combining the gas reservoir engineering and economic evaluation methods. And the reasons for the high gas recovery rate in narrow river reservoirs are also analyzed. Results show that the reasonable rate ratio for horizontal wells in this kind of reservoir is 1/6￣1/3, and the optimal gas recovery rate of the main rivers is 4%￣6%. The main reasons for narrow river tight sandstone gas reservoirs with higher gas recovery rate than conventional ones is that the wells in narrow rivers have small control reserves. For the tight sandstone gas reservoir with narrow rivers, the investment return period can be shorten and the economic benefits can be improved if a higher gas recovery rate is accepted according to the study.

10.6056/dkyqt202001018