临兴-神府区块致密气藏产水类型的水化学识别方法

A Hydrochemical Discrimination Method for Water Production Types of Tight Sandstone Reservoirs in Linxing-Shenfu Gas Field

临兴-神府区块位于鄂尔多斯盆地东缘,工区致密砂岩储层气水分布规律较为复杂,压后试气生产过程中气井产水的问题普遍存在,气井产水经常伴随气井较长的生产周期,因此有必要对气井产出水类型进行有效识别。为更准确地把握气井产水情况,以临兴-神府区块压裂试气井产出水的水化学数据为基础,选取典型样本点,通过矿化度、pH值、钠氯系数、氯镁系数及碱交换系数对地层水、压裂残液和凝析水这三类气井产水类型进行了识别划分,形成一套定量化判别指标,可对临兴-神府区块气井压后试气方案部署及生产对策提供一定的参考依据及技术支持。

The Linxing Shenfu block is located in the eastern edge of the Ordos Basin.The distribution pattern of gas and water in tight sandstone reservoirs in the work area is relatively complex,and the problem of gas well water production during post pressure gas testing production is common.Gas well water production is often accompanied by a longer production cycle,so it is necessary to effectively identify the type of gas well water production.In order to accurately grasp the water production situation of gas wells,based on the hydrochemical data of the produced water from fracturing gas testing wells in the Linxing Shenfu block,typical sample points were selected.The water production types of formation water,fracturing residual fluid,and condensate water were identified and divided through mineralization degree,pH value,sodium chloride coefficient,magnesium chloride coefficient,and alkali exchange coefficient,forming a set of quantitative discrimination indicators.This can provide certain reference and technical support for the deployment and production strategies of gas well pressure testing plans in the Linxing-Shenfu block.