四川盆地磨溪区块灯影组四段强非均质性碳酸盐岩气藏气井产能分布特征及其对开发的指导意义

四川盆地磨溪区块灯影组四段气藏储集空间多样，储层非均质性强，流体渗流规律复杂。气藏开发过程表现为以下3个特征：①气井产能差异大，以中高产井为主；②气井稳产能力差异大，大多数井稳产能力较强；③分段酸压工艺和特殊工艺井可大幅度提高气井产能。为弄清气井产能分布特征，采用气藏工程研究与综合地质研究相结合，分析气井产能在平面上的分布特征。研究结果表明：气井产能在平面上具有明显的分区分带特征。气井产能在平面上主要分布在4个区域：Ⅰ区，上覆灰岩厚度为0 m区域；Ⅱ区，上覆灰岩厚度介于0~5 m之间区域；Ⅲ区，上覆灰岩厚度介于5~20 m之间区域；Ⅳ区，上覆灰岩厚度介于20~40 m之间区域，同时建立了不同区域内气井产能与上覆灰岩厚度的拟合公式。气井产能在平面上主要分布在台缘带、台内带和坡折带3个带，气井产能由台缘带、台内带到坡折带依次减小。研究成果可有效支撑气藏开发建产区筛选、井位部署和气井产能评价。

The gas well productivity distribution characteristics in strong heterogeneity carbonate gas reservoir in the fourth Member of Dengying Formation in Moxi area,Sichuan Basin

For the gas reservoir of the fourth Member of Dengying Formation in Moxi area, Sichuan Basin, the reservoir space is various, the reservoir heterogeneity is strong and the fluid seepage law is complex. The development process of gas reservoir shows the following characteristics. (1)The gas well has a large difference in productivity, mainly in medium and high production wells. (2)There are great differences in stable production capacity of gas wells, and most of them have strong stable production capacity. (3)Staged acid fracturing technology and special technology wells can greatly improve gas well productivity. In order to find out the distribution characteristics of gas well productivity, gas reservoir engineering research and comprehensive geological research are combined to analyze the distribution characteristics of gas well productivity in the plane. The research shows that the gas well productivity characteristics have obvious subdivision of areas and belts characteristics in the plane. The gas well productivity is mainly distributed in four areas in the plane. The first area is that the thickness of overlying limestone is 0 m. The second area is that the thickness is 0-5 m. The third area is that the thickness is 5-20 m. The fourth area is that the thickness is more than 20 m. At the same time, the fitting formula of gas well productivity and overlying limestone thickness in different regions has been established. On the other hand, gas well productivity is mainly distributed in three belts which include platform edge, platform interior and slop belt. The gas well productivity decreases from platform edge, platform interior to slop belt. The research results can effectively support development area selection, well location optimization in the process of gas reservoir development evaluation and gas well productivity evaluation.