Performance simulation and perforated parameters optimize for perforated wells with compaction zone and drilling damage in tight gas reservoirs

Abstract

It is essential to understand how to improve the production of perforated well in tight reservoirs. In this paper, based on the experiment of experiment evaluation of perforation tunnel and perforation compaction zone, the drilling mud invasion zone and stress sensitivity, a new productivity numerical model is established considering the damaged zone being drilling, and the compaction zone being penetrated and the sensitivity in tight gas reservoirs. Considering perforation interaction, drill damage and seepage interference, the production rate under different parameters of perforation, compaction zone, damaged zone is discussed to yield the highest productivity. The numerical results show that it exists an optimal hole density in specific formation and when the perforated hole penetrates the invasion zone, increasing the depth of the perforation hole by the same amount would not result in a significant increase in gas production. The invasion and compaction zone permeability have little effect on the cumulative gas production, but an inflexion point still existed. Further, according to the principle of orthogonal experimental design, forty-one groups of orthogonal experimental calculations are designed and conducted. By analyzing the experimental results, the perforation density, hole diameter, invasion thickness, compaction zone thickness, invasion permeability, compaction zone permeability and stress sensitivity on productivity of perforated well is in descending order. The work presented in this paper can offer a technological basis and theoretical foundation for optimizing perforation parameters in specific tight gas reservoirs.