致密气藏压裂水平井产能计算方法

致密气藏开发普遍采用多段压裂水平井的开发模式。为了准确评价致密气藏压裂水平井产能并确定气井的合理配产，实现气井高效开发，基于保角变换理论和气水两相渗流理论，同时将基质有效渗透率作为变量来考虑压裂施工和气井产水对储层有效渗透率的影响，建立了压裂水平井气液两相产能方程。通过实际生产数据验证，结果表明：无因次泄气边界大于0.55时，气井生产压差随配产增加呈下凹型快速增长；相同气井产能条件下，水气比越大气井所需生产压差越大；水平段方向与K_y方向平行时，渗透率各向异性程度K_y/K_x越大，相同产气量时的生产压差越小；水平段与渗透率主值方向的夹角θ < 30°时，相同产气量条件下的气井生产压差几乎不变。因此，从降低压裂水平井储层压力损失的角度来考虑，布井时必须充分考虑渗透率各向异性程度和水平井水平段方向的影响，同时注意控制气井配产和采取必要的控水排水措施，以便达到更好的开发效果。

Calculation method for productivity of fractured horizontal well in tight gas reservoir

In order to accurately evaluate the productivity of fractured horizontal wells in tight gas reservoirs and determine the rational distribution of gas wells, and to achieve efficient development of gas wells, based on the theory of conformal transformation and gas water two-phase seepage theory,the effective permeability of the matrix was used as a variable to consider the effects of fracturing and gas well production on the effective permeability of the reservoir,and gas liquid two phase productivity equation of fracturing horizontal well was established and verified by actual production data. The reliability of the deliverability calculation results was verified. The results show that when the dimensionless discharge boundary is greater than 0.55,the production pressure drop of the gas well increases rapidly with the increase of production,and the higher the water-gas ratio is,the greater the pressure drop for the gas well is needed under the same gas well productivity. When the horizontal direction is parallel to the K_y direction,the greater the permeability anisotropy K_y/K_x is,the smaller the production pressure drop is needed in the same gas production. When the angle between the horizontal section and the main permeability direction is less than 30°,the production pressure drop of the gas well under the same gas production condition is almost unchanged.Therefore,from the view of reducing the pressure loss of reservoir pressure in fractured horizontal wells,the influences of permeability anisotropy and the direction of horizontal well horizontal section should be fully consi-dered,and the control of gas well production and necessary water control and drainage measures should be taken into consideration in order to achieve better development effect.