Study on productivity of horizontal wells with segmental perforation based on pseudo steady-state flow

摘要

Segmental perforation is widely used for horizontal wells.However,the flow of fluid in porous media is a com-plex problem.Using the Fourier transform,principle of potential superposition,trigonometric function transform,as-ymptotic analyses,a pressure solution of a pseudo steady-state flow model in 3D circular-boxed media has been estab-lished.Comparing with the productivity of vertical wells,an equivalence radius model can be obtained.Based on the model,a method of evaluating the productivity of segmental perforation horizontal well is presented by means of principle of superposition.It shows that the equivalence radius is different for various positions of horizontal wells;the output of both ends of horizontal wells is greater than the others under the same length of perforation interval;it is more important to obtain high productivity by increasing the length of perforation interval than enlarging the spacing between perforation intervals.The result of this research can be used to ascertain the yield of each perforated interval.