Design And Injectivity/productivity Analysis For Z-W23 Underground Gas Storage

Construction of gas storage is the safest and most effective means to solve the problem of a shortage of natural gas supply seasonality. Z-W23 underground gas storage project is a supporting project of coal to natural gas outside western pipeline project. This project can solve the problem of peaking South and South-East gas pipeline, and has a very important strategic significance for the entire Chinese petroleum and petrochemical supply pipe network security balance supply. Injection and production capability is an important criterion for gas storage capacity, and evaluation of it is the most fundamental and important work in the early construction.On the basis of the analysis of W23 gas block closed, reserves, production capacity and other characteristics of the areas, this paper’s set the main block as the analysis target, divided production area according to the situation of production capacity and established district average productivity equations; First, starting from a single well analysis, We have established a single well nodal analysis model in different areas of production capacity, and analyze the main factors affecting the injection-production capability, including tubing diameter, wellhead pressure, formation pressure. As the only controllable factor, we focused on the influence of the diameter of the injection and production capacity, and we found out that this effect can be produced vary greatly performance in different regions; In order to solve the low productivity problem in low-producing areas, we’ve calculated the capacity of directional and horizontal wells under different conditions; For gas production process gas flow rates too excessive may cause erosion problem and too low may cause the bottom effusion problem, We propose flow control requirements for different producing-areas, different tubing-diameters. These data provide reliable support for the overall design of the gas storage.On the basis of evaluation of gas reserves in the main block, we have designed storage capacity of gas storage and the upper and lower the pressure. On the basis of taking full account of reservoir properties(capacity situation), diameter, wellhead pressure and the formation pressure, combined engineering requirements, I’ve planned well network Reasonably.The maximum daily production have been calculated both new and old wells in different producing-areas of different well types.and a reasonable program of production and gas injection program has been planed within the Erosion limits and minimum carrying liquid flow rate; We simulated peaking and emergency gas supply capacity, The results meet the engineering requirements, which reflect the rationality of the well network design and Injection-production program. This paper provides a theoretical basis for Z-W23 gas storage construction.