Bottom Water In The Low Permeability Gas Reservoir Water Cone Dynamics And Rational Exploitation Of Countermeasures Applied Research

The gas reservoirs in SiChuan and CHongQing in our country have the features that being weak in reservoir properties, bearing some fractures and with some edge or bottom water. The seepage mechanism is complicated, and is difficult to exploit. During the exploitation, the fractures make the edge or bottom water whisk into well bore, which results in producing water, the production rate reducing even shutting down, and effects on gas production and life-span severely. To delay the two-phase flow of gas and water and non-water producing duration become the key point for the reasonable and efficient exploitation.The dash of edge water and coning of bottom water is a puzzle in developing low permeability gas reservoir, although there are many returns have been achieved in theory and practitical apply, the complexity of seepage mechanism, difficult in exploition make the research on the coning dynamic and the application of reasonable development game become necessary and difficulty.Surrounding the problems in developing low permeability gas reservoir, this paper analyses the geologic feature, production performance and the law of producing water, and studies the coning dynamics. At the same time, analyzes the factors controlling the productivity of low permeability gas reservoir with water.The returns from this paper as follows:(1) Based on the analysis of geologic feature and production performance of low permeability gas reservoir with water, this paper analyzes the productivity and the factors controlling the productivity of low permeability gas reservoir with water.(2) Based on the theory of gas sphere endocentric flow, the law of fluid particle motion in porous medium, and the relationship of pseudo pressure between pressure and pressure square, this paper give the function of water shape and time. The water coning high at any radius at any time before water breakthrough, and the breakthrough time can be calculated from this function. In this way we can calculate the shape of coning profile at any time, and can offer a theory reference for plan the reasonable production system.(3) This paper studied the effect of the size of water body, the net thickness of the reservoir, the rate of vertical permeability and horizontal permeability and the perforation degree of well on the coning dynamic state and production performance.(4) Taking advantage of returns of this paper, combining with the numerical simulation, this paper researches the encroachment mechanism of bottom water, and gives the reasonable development game for the M4 region of HeTianHe gas reservoir.