Reserves Evaluation Based on Reservoir Geological Knowledge Database

Reservoirs in Sulige gas field are tight and strongly inhomogeneous. The gas reserves calculated with volumetric method is not accurate due to lack of drilling, wireline logging, and well test data in the exploration phase. When the gas field is in the stable production period, more sample data are acquired; thus, we know better about the geological conditions in this area. It is necessary to calculate and evaluate the reserves again. In this paper, with strongly inhomogeneous tight sandstone gas reservoir in He8 and Shan1 member as the researching objective, we put forward the method of recalculating reserves based on database of geological knowledge about reservoir. The database of geological knowledge about reservoir was set up by analyzing reservoir configurations of well network with infilling wells at the gas field. Guided by database of geological knowledge about reservoir, we described the reservoirs thoroughly and divided the reserves calculation units. According to the thought “Dividing the reservoir into units horizontally and minor layers vertically,” we recalculate the reserves adopting volumetric method. Referred to dynamic production condition, cumulative production, abundance of reserves, and internal rate of return (IRR), we classified and evaluated the reserves in this area. According to the evaluation, we further confirmed the resource base of block stable productivity, thus suggested the advantageous targeted block for production construction. In a word, the evaluation method is a guide to the recalculation and comprehensive assessment of strongly inhomogeneous tight sandstone gas reservoir in this paper.