Reliability Allocation of Compression Packer Based on Fuzzy Analytic Hierarchy Process Method

Abstract The packer is a key component of the downhole sealing system during well completion stage, and its sealing reliability is directly related to the effectiveness of the downhole sealing system. The reliability assignment of the packer should meet the multi-level and multi-factor requirements, and it has the coexistence of quantity and quality analysis. Thus, how to achieve the reasonable reliability allocation of the packer is very important. This article introduced the reliability allocation for a typical compression packer based on the fuzzy analytic hierarchy process (FAHP) method. The structure of analytic hierarchy process for compression packer’s reliability allocation was established, which include the target layer, criterion layer and object layer. To quantitatively calculate the weights of the main part of the compression packer system, the FAHP method was performed, which consist of the sealing unit, anchoring unit, locking and anti-retreat unit, seating unit, unseating unit and anti-open unit. The three-scale judgment matrix scale was conducted to make the fuzzy consistency matrix meet the consistency conditions. Based on the weight analysis results and the preset reliability, the reliability allocation of the compression packer system was performed. The obtained distribution results satisfy the preset requirements and consistent with the actual operation of the packer, which proves the feasibility and validity of FAHP method. The proposed method reasonably solves fuzzy decision-making problem in the process of reliability allocation, and provides an efficient and reasonable way for the reliability allocation of the packer.