Cemented Multi Stage Fracturing Completion System – An Alternative to Open Hole MSF and Plug and Perf

Abstract

Open Hole Multi Stage Fracturing (OH MSF) completion system technologies and Plug and Perf (P&P) technique are being utilized with the goal of increasing hydrocarbon production for years. However, due to unfavorable open hole well conditions, increased number of stages and limitations of open hole packers under challenging HPHT environments, some of OH MSF completions planned are converted to cemented liners. P&P is the only option for multi stage fracturing in the event of cemented liner completions. This paper discusses if cemented MSF can be an alternative to OH MSF completion systems as well as P&P and expands the technology portfolio for multi stage fracturing. The new cemented MSF completion system consists of a cementable hydraulic frac port opened by applying pressure in the first stage and multiple cementable fracturing ports for the next stages that are opened by dropping activation balls during rig-less fracturing operations. Stage zonal isolation is not dependent on mechanical, swellable or metal expandable packers and relies on cement behind the completion. Zonal isolation can be achieved with cement in the absence of gauged hole. The deployment of the lower completion is much less sensitive to the washed out or over gauged hole condition than that of an OH MSF system. Moreover, cement on the annulus ensures integrity of stage isolation while minimizing liner deformation and maximizing full well accessibility after multi-stage stimulation treatments. This was the first time a 15k psi pressure rated cemented multi-stage fracturing completion system was successfully deployed and stimulated through in the area. The implementation had qualified and field-tested the novel completion methodology which resulted in successful multi-stage stimulation operations. Production rate was enhanced in the well completed with the cemented MSF when compared with offset wells having OH MSF and P&P completions. The novel system without isolation packers and less string stiffness was easy to deploy and allowed for precise frac initiation point through continuous cement behind the liner. Compared to P&P, the cemented MSF system maximized the operational efficiency and cost saving by eliminating the need of wireline perforation and frac plug milling with CT. To address the challenges encountered in deploying OH MSF completions, cemented liner and P&P operations, it was necessary to develop a new completion strategy providing commercial production rates comparable to results achieved from OH MSF completions. This paper seeks an answer to whether cemented MSF completion system can be an alternative to OH MSF systems or P&P technique. Successful implementation of a cemented MSF completion that utilizes cementable sleeves capable of withstanding high fracturing pressures and harsh environments improves attending tight formations in an efficient and cost-effective manner and diversifies the efforts in exploiting tight HPHT formations.