Unconventional Completions - an Operational Comparison

Abstract

Abstract In the last seven years the oil and gas industry has seen significant changes in the price and supply of hydrocarbons, and new production from low-permeability unconventional reservoirs that require multistage hydraulic fracturing is playing a major role in the additional supply. To effectively produce these reservoirs, reservoir characterization, horizontal drilling, multistage completions, and multistage hydraulic fracturing are requirements in most plays. Most of these technologies have been used in other applications for many years, but combined they provide the key to unlocking these reservoirs that were considered uneconomical in the past. This paper will focus on the wellbore completion technologies that enable hydraulic fracturing of multiple stages. Three completion techniques have emerged as the most effective and efficient in these types of formations: plug-and-perf, ball-activated frac sleeve completions, and coiled tubing-activated completions. All these wellbore completions serve the same functions of providing annular isolation, through-tubing isolation, and diversion needed to hydraulically fracture multiple stages, but each has different methods and devices of doing so. Recent advances in technology have enabled all three completions to use cement or openhole packers to provide the required annular isolation, so if one method of isolation is proven to be superior in one application, any of the three completion techniques can be used. Now the question is, "How do I choose the right completion for my application?" The deciding factors to answer this question now become operational efficiency, cost, logistics, flexibility, and application. This paper will present several scenarios where one type of completion system could be more beneficial or efficient in certain applications. The benefits and considerations of each completion must be analyzed to select the most efficient completion for certain applications. The primary purpose of this paper is to discuss these benefits and considerations and how they compare in different applications from an operations point of view.