Production characteristics and the optimization of development schemes of fractured gas reservoir with edge or bottom water

Abstract

This paper discusses the production characteristics and development scheme of gas reservoirs and gas condensate reservoirs with edge or bottom water and oil ring or bottom oil. The characteristics of this type of gas reservoir are the followings: (1) pore is the main storage space of fluid; (2) fracture is the main percolation flow channel; and (3) the distribution of pore and fracture is seriously heterogeneous. During the development process of the reservoir, its dynamic performance mainly are: edge or bottom water and oil will easily flow to producer along the high permeable fracture channel; and water influx into the gas bearing area will heavily influence gas production, for example, forming gas, water (and oil) multi phase flow, decreasing gas rate of producer, forming some water locked gas bearing areas and reducing the recovery of gas and oil. The watered out mechanism and its harm extent are discussed. Based on the principle of balanced production, this paper offers the optimal development scheme to avoid water influx, enhance gas and oil recovery and improve economic benefit. Three examples of mature gas fields are given in this paper.