Research Of Perforating Schemes Based On Multi-objective Optimization

Perforation is one of major oil and gas well completion methods. Perforation parametersinvolve perforation diameter, shot density, perforation phase angle, hole depth, etc, anddifferent perforation parameters have different influences on oil-well productivity. Research onoptimization of perforation scheme has a crucial role in improving the perforation capacity,reducing the cost of perforation and safety production.In the tradition way, the optimization of perforation scheme depends on human’ssubjectivity and experience so that it will strongly influence decision result. In this paper, theinfluence factors of perforation completion was analyzed and the multi-objective optimizationalgorithm is mainly studied. After that, a scientific decision-making optimization algorithm ofperforation scheme is established by combing swarm intelligence algorithm with TOPSISalgorithm.Firstly, particle swarm optimization and ant colony algorithm were studied and improvedso as to solve multi-objective optimization problems. Multi-attribute decision making problemwas studied, and an improved TOPSIS algorithm was proposed based on combing the methodof maximum deviation with TOPSIS algorithm.Secondly, the influence of perforation parameters on perforation capacity ratio anddecreased value of perforated casing strength was analyzed. And quantitative analysis modelof capacity radio and casing strength reduction coefficient was determined based oncorrelational studies of perforation completion at home and abroad.Finally, in order to solve the problem of optimization of perforation scheme, optimizationmodels were proposed respectively combing multi-objective particle swarm optimizationalgorithm and multi-objective ant colony algorithm with TOPSIS method. Perforationcompletion scheme decision-making system was developed based on the above two algorithmmodel. By using scientific method to make decision of perforation scheme, this system canreduce blindness and subjectivity in the process of decision-making as far as possible, and itcan provide a scientific guidance on perforating operation.