Study On Seepage Mechanism And Development Technology Policy Limits For X Gas Reservoir With Low Permeability And High Water Saturation

Low permeability gas reservoirs have poor pore and permeability properties,and special well types and certain stimulation measures are often needed to put them into economically and effectively developed gas reservoirs.At the same time,low permeability gas reservoirs,in addition to low porosity and permeability,often have high water saturation,resulting in water production of gas wells.The above unfavorable factors make the development cost of low permeability gas reservoirs high,resulting in many low permeability gas reservoirs at the edge of economic development,or in the state of no development value and no economic and effective use,especially in the high cost of development of low permeability offshore gas reservoirs.To achieve economic and effective development,more economic and technological problems need to be explored and solved.The X gas reservoir still faces many difficulties in development.:?It has deep burial depth,high temperature and high pressure characteristics,which require high development technology;?Reservoir property is poor;?Large pore-throat ratio is easy to cause water lock;? High movable water saturation that makes serious water production problem;?Development costs and the demand for single well productivity are high.According to the above problem,This paper mainly obtained the following achievement:1)On the basis of summarizing the basic geological characteristics of X gas reservoir with low permeability and high water saturation,the difficulties in gas reservoir development are analyzed,and the abandoned pressure and theoretical fracturing horizontal well productivity are determined.2)Based on the theory and method of gas reservoir engineering,the influence of temperature and pressure on Gas-water phase permeability is analyzed,and the gas-water seepage characteristics of X gas reservoir are analyzed by high temperature and high pressure gas-water phase permeability experiment.3)The parameters of fractured horizontal wells in X gas reservoir with low permeability and high water cut are optimized by numerical simulation technology.4)By introducing reservoir comprehensive parameters considering the productivity of fractured horizontal wells and cumulative production requirements of single well,under the condition of economic benefit constraints,the comprehensive parameters chart of development lower limit is determined,which provides a reliable basis for gas reservoir development mode and development area optimization.5)Based on the geological model of X gas reservoir with low permeability and high water cut,the horizontal well direction and gas production rate are optimized,which provides an effective water avoidance scheme for the development of the target gas reservoir.