The Research On Variable Shooting Density And Selectively Perforation Of Horizontal Well Completion

With the advancement of the horizontal well technology and the increasing number of horizontal wells, more and more emphasize is put on the research about perforated wells completion in horizontal wells. Some troublesome problems such as the high cost of perforation, the bottom water coning, etc, are contained in perforated completion of horizontal wells. In this work, being based on decreasing the cost of perforation and deterioration of annular tube, protecting the bottom water coning and raising production of perforated horizontal well, four models are established. the model of conventional horizontal well perforated completion, analyzing the effect of perforation parameters to output and optimizing the respectively parameters of perforated horizontal well by using orthogonal test; The model of length optimization of horizontal wells, which can optimize the length of horizontal wells basing on black oil model; the model of selectively perforated horizontal well completion optimizes schemes of selectively horizontal well perforated completion;the model of variable density perforating completion of horizontal well contains three models, the fluid flow model through porous medium, the perforation flow model, the pressure gradient model of well bore flow and the flow coupling model based on analyzing production flow pressure dropdown of perforation horizontal wells.and could optimize the affluence lateral section of perforated horizontal well. By using the VB program, an engineering designing software is developed according to those models. Four conclusions are obtained. First, in the progress of conventional horizontal well perforated completion, every factor has a certain range of influence and its own weight. Considering all the factors'weights comprehensively, the maximum output can be obtained. Secondly, in the process of horizontal well perforation completion, only a certain length of the horizontal well needs to be opened instead of perforating the whole horizontal well, while the effect has no difference. Then, not only the production can be accomplished as the whole horizontal well perforated, but also the cost is saved, when horizontal well-bore is divided into 5 average segments of which two segments, the heel and the toe, are perforated and the irreducible segments avoid to be perforated. At last, in the progress of variable perforated density perforating to horizontal well completion, using the optimized perforated density, fluid inflowing section can be uniformed, bottom water coning was protected and the cost of perforation was decreased. In this study, theoretical foundation and optimization means are supplied for horizontal well perforated completion, perforated level of horizontal well are advanced, and also, the research has very important instruction function to the horizontal well development effect's enhancement.