SUMMARY
Hydrochloric acid (HC1) stimulation is a common method of removing shallow damage in carbonate formation completions resulting from drilling and workover operations. Current practice in the Ghawar Field is to bullhead large volumes of acid into the power water injection (PWI) wells to stimulate the long, open hole completions in the Arab-D formation. Small stages of particulate materials in a viscous carrying fluid are normally included in the treatment for diversion. This report describes the field testing and evaluation of three different acid treatment designs; (1) the conventional, bullhead treatment, (2) a coiled tubing placed, nitrogen foam diverted treatment and (3) a coiled tubing placed treatment without diverting materials. The treatment designs utilizing coiled tubing were developed in an effort to improve upon the conventional method by providing better formation damage removal throughout the entire porous interval and to reduce costs. A review of the conventional bullheading technique is presented along with case histories of wells that were stimulated with the two treatment techniques utilizing coiled tubing placement. The data presented indicates that the treatments combining coiled tubing placement and nitrogen foam diversion were more effective in stimulating the Arab-D formation and in improving injectivity than the conventional bullhead jobs.
TX 75083-3836, U.S.A., fax 01-972-952-9435.
AbstractDrilling horizontal wells has become the more commonplace in many Saudi Aramco fields. Recent advances in drilling and completion practices enable the drilling of more complex wells with various types and shapes such as extended reach wells, bi-laterals and multi-laterals for providing maximum reservoir contact. These complex wells impose great challenges with respect to rigless well interventions. One of the initial well interventions, which follow drilling completion, is acid stimulation to remove formation damage. The challenges raised because of well complexity include accessing the laterals, reaching the end of each lateral and properly distributing treatment fluids over entire horizontal sections.Effective rigless interventions in these challenging wells have limitations and technologies are still evolving. Deployment of tools and fluids downhole is no more possible through conventional coiled tubing applications. New techniques have been developed to assist coiled tubing (CT) to access laterals and extend their reach. In addition, recent advancement of CT bottom-hole assembly (BHA) allows combining services of more than one function such as deploying tools and fluids and at the same time acquiring vital downhole data.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.