15K Multi-Entry Cemented Multi-Stage Fracturing System-Alternative Completion Method for Deep Tight Gas Wells

Abstract

Multi Stage Fracturing (MSF) completion technology with a true 15,000 psi pressure rating, Multi-Entry (ME), cementable system was developed for utilization in deep tight gas wells. The new completion system brings operational and design improvements to the MSF methods utilized for these types of wells. This paper discusses the details on the development of the novel system considering harsh well conditions, its multi-entry design for creating multiple fractures across each stage, and improvements compared to the traditional open hole MSF solutions. A detailed review of the requirements for the completion installation, activation, fracturing execution and expected performance metrics will also be covered. The new cemented MSF completion system consists of a cementable hydraulic toe sleeve and cementable fracturing ports. The toe initiator placed in the first stage is opened by applying pressure whereas multiple cementable fracturing ports in the remaining stages are opened by dropping a single size ball in each stage. Zonal isolation relies on cement behind the completion rather than mechanical, swellable or metal expandable packer as in regular Open Hole (OH) MSF systems. To verify the completion system suitability for the target application, a thorough design of the system components and qualification testing were needed. Collaborative approach, clear project scope definition and detailed review of the solution were key factors to ensure final product met expectations. Several wells completed and stimulated successfully with the new ME MSF system will be discussed. It is observed that the slim design, rotatable feature was mitigating the challenges, reducing the overall risk of deployment. In addition, stimulating of stages using a single ball per stage activating multiple sleeves in each stage, except for the first stage which was with cementable hydraulic sleeves, resulted with more efficient fracturing operations by reducing time, resources, and emissions. The 15K cemented ME MSF completion system provided a third MSF option to complete deep tight gas wells in addition to the current two methods of cemented liner and open hole MSF completions. It bridges the gap between the current systems by relying on the cement for zonal isolation and allowing multiple sleeves in each stage, imitating clusters used in Plug&Perf (P&P) operations. The system eliminates isolation packers compared to open hole completions and perforation, plug setting, plug milling when compared to P&P cemented liners technique in which wireline and coiled tubing interventions are required.