克拉玛依油田八区下乌尔禾组油藏水淹层识别

Identification of Water Flooded Zone of Lower Wuerhe Formation in District No.8 of Karamay Oilfield

根据克拉玛依油田八区下乌尔禾组油藏地质和开发动态,分析水淹层的测井响应特征,研究了油藏水淹状况,提出了裂缝性低渗透砾岩油藏注水开发中后期水淹层的综合识别方法,并对三次加密调整井进行了水淹层解释。调整井投产效果证明,该方法的符合率高达93.8%。研究认为水淹层的分布受裂缝和注水量的控制,在平面上水淹方向以东西向为主,南北向其次;在纵向上以顺层水淹为主,水淹程度受油层打开程度和裂缝发育程度影响,P_2w_3、P_2w_4水淹相对严重。水淹体的形态受裂缝形态控制,全区平均水淹体高度为80～120m,长度300～500m,厚度在100m左右。

Based on the geologic feature and the development performance data of Lower Wuerhe reservoir in District No.8 of Karamay oilfield, its well log response characteristic is analyzed. The comprehensive identification method for water flooded zone of fractured low permeability conglomerate reservoir at the mid-late stage by water flooding process is proposed. The water flooded zones in tertiary infilling adjustment wells are explained. According to the production rates from these adjustment wells, the results from this method are coincident with the actual conditions by 93.8%. Also, the factors affecting the water flooded degree are analyzed. It is recognized that the distribution of water flooded zone is mainly controlled by fracture and water injection rate. In plane, the water flooded feature is dominated by injected water flooded type of EW direction followed by NS direction; while in the vertical, dominated by bedding water flooded type, in which the water flooded degree is generally affected by the openness of corresponding oil layer and the development of fracture system. The water flooded degrees of P2w3 and P2w4 are relatively serious, with 80-120 m in water flooded height, 300-500 m in the length and about 100 m in thickness.