Research And Application Of Dynamic Characteristic Evaluation Method For SN Fractured-Type Gas Reservoir

The Ordovician gas reservoir in the SN area is a deep carbonate fractured-cavity gas reservoir.Currently,there are 16 wells in total,of which 6 wells have been tested to obtain industrial gas flow.The initial single well test has higher production capacity,but it decreases rapidly.In addition,it is difficult to explain the Ordovician fractured-cavity gas reservoir by using conventional gas well pressure recovery test data interpretation methods.In view of the above problems,this article takes the Ordovician Yijianfang Formation and Yingshan Formation gas reservoir in SN well area as the research object,and uses gas reservoir engineering theory as the guide to combine geological,drilling,well completion,well logging,and test data.Together,analyze the gas reservoir type,reservoir model,and test production dynamics.A well test interpretation model was established based on the geology and fluid characteristics of the well area,and the parameters of the fracture and void were obtained by fitting.Based on the above,the dynamic reservoir reserves and productivity evaluation were carried out.The main research results of this paper are as follows:(1)The block profile study shows that this area belongs to high-temperature and high-pressure dry gas reservoirs,which are mainly fracture-hole and fracture-cavity type reservoirs.(2)According to reservoir characteristics and fluid flow law in the study area,four well test models with different types of fractured-cavity gas reservoirs were established.After solving and inverting,typical models of each model were obtained and sensitivity analysis was conducted.The influence of fracture parameters on the shape of the curve.(3)According to the fracture-hole model to explain the characteristics of the fracture cavity,use the pressure recovery method to calculate the control volume of the single well and complete the evaluation of the gas well dynamic reserves.(4)Under the condition that the test data is limited,the production data fitting method is used to evaluate the production capacity of the area,and the reasonable production distribution is discussed through the common node analysis method.