New Hydra-Jet Tool Demonstrates Improved Life for Perforating and Fracturing Applications

Abstract

Abstract Hydrajet perforating and fracturing has recently gained popularity in the oilfield industry, especially when used with coiled tubing (CT). With coiled tubing, the task of placing many cuts at multiple places becomes straightforward and no longer time consuming. However, hydrajetting equipment life has been plagued with rapid failures, resulting in the need for time-consuming and costly tripping out and in the hole for jetting tool replacement. To reduce or eliminate such tripping costs, substantial improvements of the hydrajetting tools are required. A mere change of materials or a redesign using concepts that follow the customary models has resulted in insignificant performance improvements. It was therefore decided that a complete overhaul of the design concepts needed to be made. By doing this, substantial improvements can be obtained. This paper discusses unique improvements that have been made to the hydrajetting tools. The new tools address the aspects that have contributed to failures in the past. By taking a fresh perspective of this situation, a performance improvement of 200-300% can be attained. Recent perforating and stimulation experiences in the field demonstrate this and are discussed. Introduction Hydrajetting technology has been in use in various industries since the early 1960s (Summers 1995). From cleaning applications, such as vehicle cleaning or pipeline deposits removal to cutting applications such as cutting steel plate in fabrication or cutting rock slabs in quarries, the hydrajet tool has progressed from a simple tool for removing debris to a tool with tremendous power and accuracy. The tool has advanced from a simple tool with holes to a tool with carbide inserts or even eductors for injecting abrasives into its high-pressure fluid streams. In the oil industry, hydrajetting has been prevalent in scale removal, offshore wellhead removal, and decommissioning of offshore rig platforms. The use of hydrajet equipment also has been very successful in removing burning wellheads in war-torn areas of the Middle East. Success has also been demonstrated in perforating for well production and stimulation (Surjaatmadja, Abass, and Brumley 1994; Surjaatmadja 1993), and lately, for the stimulating process itself (Surjaatmadja et al. 2003; Rodriguez et al. 2005; McDaniel et al. 2004; Surjaatmadja et al. 2005; McDaniel et al. 2006; Surjaatmadja 2007). Because hydrajet cutting employs the use of abrasives, its life is generally limited. In surface or near-surface applications, this factor has been an acceptable risk because regular jet replacements are simple and generally not costly. In deep wellbores however, the primary expense of replacement lies in the cost of tripping, which is time-consuming and therefore expensive. Excessive tripping in and out of the hole to perform tasks is less desirable, yet often acceptable in the oil field today. However, the increased use of hydrajetting in a competitive market for stimulating and perforating, combined with increasing rig costs, has created a situation in which finding ways to reduce costs has become essential. Improving the strength of the jets has demonstrated excellent results, but efforts to continually improve the tools using conventional means may have reached a plateau (high but nowhere else to go). A totally new, patent pending concept is therefore being introduced to both improve the performance and life of jetting equipment in the oil industry.