Horizontal Wells And Multi-branch Well Test Interpretation Method

Horizontal wells and Multi-lateral wells are one of most important scientific technical progress on oil industry., and are one of most potential E&P technology in creasing oil and gas economical deliverability. The unsteady porous flow in horizontal wells and multi-lateral wells is a complicated study of mechanics through porous media. And well test interpretation of horizontal wells and multi-lateral wells based on these problems exhibit many disadvantages and luck.For the overcome of above problem, horizontal wells and multi-lateral wells are investigative objective. Based on basic theory of dynamic of fluids through porous media and reservoir characteristic, the paper investigated well test interpretation method and theory of horizontal wells and Multi-lateral wells by using reservoirs geology, porous flow theory, resource function, Green function, discretization theory, partial differentiations, numerical analysis and so on. Following results have been presented:1)By using point resource function, Green function, superposition principle, discretization theory etc. This paper presents the 3D unsteady porous flow models of horizontal wells and Multi-lateral wells in layered reservoir with impermeable boundary, constant pressure boundary, mixed boundaries etc. And the model was solved in Laplace domain space2) Applying discretization mechanism to multi-lateral wells, the unsteady pressure ofdiscrete points take into account interference between discrete points. And draw pressure and pressure derivative type curve, analyzed unsteady porous flow characteristic of horizontal wells and multi-lateral wells, classified flow regime.3) Based on above research, the paper researched that reservoir thickness, well locationreservoir boundary etc affect on unsteady porous flow characteristic of horizontal wells, and studied that well number, well distribution, well length etc influence on unsteady porous flow characteristic of multi-lateral wells.4) The unsteady pressure solution of flow regimes of horizontal wells and Multi-lateralwells are simplified, and these approximation solution were inverted to real domain, and obtained corresponding analytical solution.5) Well test interpretation of horizontal wells and multi-lateral wells were applied toexample of 3 horizontal wells and one multi-lateral wells of some offshore field. The well test interpretation was verified, and obtained some reservoir parameters.