鄂尔多斯盆地东缘临兴地区致密储层产出水赋存特征及开发启示

Occurrence characteristics and development enlightenment of produced water in tight reservoir in Linxing area,eastern margin of Ordos Basin

鄂尔多斯盆地东北缘临兴地区致密气储层测试产水问题突出,为了明确该区致密砂岩储层产水主要来源,从区域水文地质条件分析着手,通过地层产出水样分析实验、半渗隔板实验,分析了研究区地层水化学特征和赋存状态。结果表明1)研究区致密砂岩储层产出水为成藏后地层内滞留水,产出水以地层内自由水和毛管水为主,受压裂沟通及生产压差影响产出;2)Ⅰ类高孔渗储层水以高可动水储层为主,是“避可动”的主要目标;Ⅱ类储层水主要以毛细管水为主,是“控转化”的主要目标;Ⅲ类储层水以毛管水、束缚水为主,是“限压裂”的主要目标。以上成果认识对盆地边缘低压、低饱和度致密气藏开发具有一定指导意义。

Water production problems of tight gas reservoirs test are prominent in Linxing area,northeastern Ordos Basin.In order to clarify the main source of production water of tight sandstone reservoirs in this area,that analyze the regional hydrogeological conditions first,also analyze the chemical characteristics and occurrence state of formation water by water sample analysis experiment and semi-permeable diaphragm experiment.The results showed that:1)The production water of tight sandstone reservoir in the study area is retained water in the formation after reservoir formation.It is mainly free water and capillary water in the formation,which is affect by hydraulic fracturing and production pressure.2)The movable formation water in type I high porosity and permeability reservoir is mainly free water,which is the main target of“avoid movable”;the movable water in type II reservoir is mainly capillary water,which is the main target of“controlled transformation”;the formation water in typeⅢreservoir is mainly capillary water and bound water,which is the main target of“limited fracturing”.The above results have certain guiding significance for the development of low-pressure and low-saturation tight gas reservoirs at the edge of the basin.