New Jetting Assembly for Enhanced Filter Cake Cleanup During Lower Completion Installation

Abstract

A study on past water injector well performance indicated that soaking the OH with DIF breaker was not effective at removing filtercake, especially when compared with wells that had a post-completion stimulation. Analysis of the data suggested that long term injectivity/productivity could be improved at lower cost if a stimulation could be performed during the lower completion operational step. A new technology to precisely inject and divert acid, through the screens, towards the filtercake during the lower completion installation was developed, thoroughly tested and finally trialed in a well, to verify the results and validate the theory. A jetting tool assembly was developed, with the goal to improve clean-up by impelling acid through the screens and against the filtercake, adding agitation (previously unavailable through soaking placement) leading to a more thorough filtercake clean-up during lower completion installation. The assembly ran in hole includes a high-pressure jetting tool designed to divert the acid to every inch of formation for a very thorough filtercake removal, and it is powerful enough to jet through the screens and reach the formation face. The development process included the expansion of the jetting tool's capability to pump at higher rates, and the addition of two flow control tools to assist the jetting tool to function at will, while maintaining all typical lower completion service tool functionalities prior to its activation. Once the tool was developed, a series of successful tests were carried out, culminating with a full-scale SIT on a rig, to fully test all the capabilities of the tool assembly. Finally, the technology was successfully trialed in an deepwater injector well in the Gulf of Mexico (GoM) to acid jet the filtercake, achieving very positive initial results, which support expansion of the technology's use to other assets and well types. High pressure jetting tools have been used before with coiled tubing deployment, but never during a lower completion run. Through the development of the new tools, and the expansion of the jetting tool capabilities, this new approach allows the operator to save significant post-completion intervention costs by adding the stimulation capability to the completion phase of the well, obtaining a significantly better well performance at a reduced cost. This is especially significant in deepwater wells.