Fine Reservoir Description In A-116 Area Of Hujianshan Oilfield

The Chang 1 reservoir in AN116 area of Hujianshan oilfield is located in Dingbian County,Shaanxi Province,and its structure is located in the middle and north part of Shanbei slope.The development in the area has been relatively stable since production was established.Since 2016,the moisture content of some oil wells has increased by a large margin,from65.6% to 76.9%,leading to an increasing natural rate of decline reservoirs,which is 27.6%.And the combined rate of decline is 27.0% from January to May 2018.Water drive condition becomes worse.In 2018,the degree of water driving decreased to 55.6% compared with56.8% in 2016.The water absorption of comparable wells gradually changed from uniform water absorption to finger-shaped and peak-shaped water absorption,and the water absorption status became worse.At the same time,some oil wells in the thick bottom water area in the western part of the reservoir have found injected water,in the eastern low-pressure area,the local injection water will be injected into the reservoir in one direction,and the whole water drive will be worse.In this paper,the basic research of reservoir geology,such as sedimentary microfacies,fine description and comprehensive evaluation of reservoir,is carried out through the comparison of fine and small layers of each layer in Chang 1 and Yan 8,and the research of geological characteristics on development and production are analyzed.The fine 3D geological model of each substratum of Chang 1 and Yan 8 are established.On the basis of geological modeling and numerical simulation with block dynamic data,reasonable development technical policy limits and comprehensive development scheme are proposed and optimized to guide oilfield development.