Successful Application of Plug and Hydrajetting Technique during Multistage Fracture for Horizontal Wells with CT

Abstract

Abstract This paper presents an alternative for operators regarding tools and methods using coiled tubing (CT) during the implementation of horizontal completions. To help address challenges faced developing horizontal completions, both cemented liners and open holes have been widely used in conventional and unconventional reservoirs. Various completion techniques have evolved from traditional tubing conveyed perforation (TCP) and plug setting, and hydrajet assisted fracturing has become the preferred pumpdown technique within the last six years in northern Mexico. The criteria used to determine the completion technique is based on three parameters—extension of horizontal length developed [well geometry, dogleg severity (DLS), deviation], fracture design (pump rate, number of intervals) and type of reservoir being exploited. For the case discussed, a pumpdown technique was selected. Pumpdown techniques are considered one of the fastest completion techniques to provide mechanical isolation between fracture stages; nevertheless, it has not been completely effective during all stages. Some of these techniques can cause premature setting of bridge plugs because of poor sand displacement or adverse well geometries, including high DLS. During the application of this technique, CT interventions are primarily considered in the event of contingencies, such as screenouts (sand cleanout) and plugs prematurely setting (plug millouts). Even though no completion operation is immune to contingencies and associated costs and nonproductive time (NPT), a constant repetition of them because of inherent well conditions or poor fluid admission by the formation increases associated completion costs and diminishes equipment efficiency in place (frac set, logging unit). As a result, CT has become an effective solution with the development of new tools and techniques to avoid such contingencies. This paper develops the concept “plugging and jetting,” wherein a mechanical isolation bridge plug (BP) is placed with CT, allowing abrasive perforations to help the producing formation communicate with the wellbore in a single run, thus allowing reduction of NPT up to 30% and providing a new alternative for horizontal completions. This paper presents case histories with benefits and results. Bottomhole assembly (BHA) design considerations with improvements that provide a new alternative to operators are also presented. This method allows completion of fracturing stages in a continuous manner, thus being advantageous in terms of operational time reduction and consequently cost savings.