Evaluation of Completion Techniques for a Tight Gas Reservoir
Engineering Honours, 2007
University of Adelaide
The determination of the most optimum completion types that can be employed in all reservoirs, let alone a tight gas reservoir, can be quite a challenging task. The main focus of this project is to evaluate better completion techniques for a tight gas reservoir. This involves a comprehensive review of the challenges that are often faced in the completion of a tight gas reservoir. A fundamental understanding of the mechanics of each completion types has also been outlined from a tight gas reservoir point of view. The presented case study encompasses an investigation of the performance of various completion options in a typical tight gas reservoir using widely used commercial simulators such as PROSPER and NETool TM.
A range of sensitivity analyses has been conducted in the PROSPER software to further evaluate the possible factors that can affect both inflow and outflow performance in a typical tight gas reservoir. The generation of production profiles along the wellbore length using NETool TM allows an in depth investigation of the performance of various completion types in a tight gas reservoir. The presented case study also all the identification of key factors that can affect well performance, such as water production and condensate-gas ratio, can be beneficial in the design of a well completion in a tight gas reservoir. This will further enable the determination of the most appropriate tubing size to be used in a well completion design, and whether a zonal isolation or a water/gas shut-off feature is required to be implemented. A cost study analysis is also carried out to determine the economical viability of each of the completion options.
The use of an integrated work-flow approach can be expected to lead to an improved well completion design selection. The structured work-flow is designed to walk through a series of steps that involve a comprehensive evaluation of all of the common challenges encountered in the completion of a tight gas reservoir, which further incorporates the evaluation of the advantages and the disadvantages of all the general completion options. A complete understanding and a thorough evaluation of all the completion techniques in a tight gas reservoir can help pave the way in the determination of the most optimum well completion design selection.