Experimental analysis of factors influencing the development effect of multilayer gas well

Abstract

Sulige gas field is characterized by complex pore structure, poor reservoir properties and low output of single-layer production. Therefore, in order to obtain higher economic profit, multi-layer commingling development is adopted in this type of gas field. According to the basic characteristics of the upper Paleozoic reservoir in Sulige gas field, there is a positive correlation between the output contribution rate of each production layer and its physical parameters and effective thickness. In order to directly analyze the inter-layer output law and its influencing factors of gas wells, a variety of formation models are designed, and the experiment of single-layer development and multi-layer combined development is carried out. It is found that permeability and original formation pressure are the main factors affecting the development effect of multi-layer well. The original formation pressure has the greatest influence on the ultimate recovery, while the permeability has the strongest influence on the average daily output and the yield contribution rate of productive layer. According to the similarity theory, the mathematical model between the gas productivity index per meter per well and permeability is fitted. Finally, the mathematical model is applied to 18 gas wells of the S-af area of sulige gas field, and the calculation accuracy reaches a high level. The validity and practicability of the formula is verified, which can provide the basis for subsequent production.