Loading...

Finite Element Analysis of Contact Pressure for Dual Completion Packer Seal Element

Korani, Mohammad Hadi | 2022

192 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 55159 (08)
  4. University: Sharif University of Technolog
  5. Department: Mechanical Engineering
  6. Advisor(s): Arghavani Hadi, Jamal
  7. Abstract:
  8. The current research was conducted to investigate the sealing behavior of single-string and dual-string completion Packer. In order to transfer the oil from reservoir located underground to the surface, the string of tubings is used which is called oil well completion string. A typical completion string not only consists of tubings but also the other facilities such as safety valve, traveling joint, sliding side door and Packer as well. Some reasons including: the cost of drilling and challenges in setting wellhead equipment at some geographical situations, producing more oil and gas lead to extraction oil form more than one zone in the oil well. In addition, taking into the account that, the different layers of earth have their own special hydrocarbon compositions, using more than one string in one oil well is highly recommended and can meet all noted points.Packer is the most crucial part of each completion string, which seals the environment enclosed by tubings and well casing. Consequently, the hydrocarbon fluid has to flow into the tubing string. Elastomeric seal element is the main segment of all packers. Axial load compresses the elastomeric seal elements situated between two rigid plates which results in radial expansion of elastomer and sealing of well casing. Unlike most of single-string packer, the dual ones are not axisymmetric which origins of packer sealing failure of the dual-string packer in some points. To tackle these problems, at the beginning, the axial deformation of an elastomeric cylinder between two rigid plates due to axial load, was simulated. The simulation was gradually developed to single-string elastomeric seal element and dual-string one. The selected hyperelastic model to represent the mechanical behavior and stress-strain curve of elastomer was Mooney-Rivlin model. Abaqus/CAE® Dynamic Explicit is used as main solver of simulations. Moreover, to enhance the precision of results generated by Abaqus/CAE® Dynamic Explicit, the compressibility coefficient (D1) was defied as 0.005 MPa-1. The sensitivity analysis was conducted to look into the behavior of dual-string elastomeric seal element. Based on the results of this analysis, some effective solutions to dual-string sealing issue, were founded and proposed.Due to the geometrical obstacles and limitations of positioning and aligning other equipment in the strings, using the new geometry of seal element and its rigid plates was chosen among all answers. Use of the new geometry of seal elements led to nonzero contact pressure in the whole mutual surface of seal elements with casing and tubings. Finally, by obtaining a suitable solution and a new geometry, the Taguchi method was applied for optimization of some of the effective parameters of the two-string seal element. Thanks to the optimization, the contact pressure increased by about 111% compared to the initial state.
  9. Keywords:
  10. Oil Wells ; Taguchi Method ; Waterproofing ; Elastomers ; Well Completion ; Sealing Element ; Finite Element Analysis

 Digital Object List

 Bookmark

No TOC