Coiled-Tubing Technologies Improve Shale-Play Development Efficiencies

摘要

Development of U.S. shale plays has greatly accelerated throughout the past decade and will continue to contribute increased production of gas and hydrocarbon liquids for many years to come. A March report by HIS-Cambridge Energy Research Associates estimates that in 2000, shale gas was only 1% of total production in the U.S., but it now makes up approximately 20% of the total production with the potential to contribute greater than 50% by 2035. The two main technologies attributed with the successful growth in shale-play development are horizontal drilling and fracturing technologies. Coiled-tubing (CT) equipment and technologies have also aided in the rapid and economical development of shale plays. The demand for these services has increased such that a CT unit is now assigned to each frac crew. Because of CT’s capability to continuously circulate, work with live-well pressure, and push to the toe of long, horizontal sections, several tools and methods have been devised to transfer these advantages to stimulation and well-servicing solutions to help optimize production while minimizing time and cost. These technologies include hydrajet and CT-conveyed perforating techniques as well as accurate placement of stimulation treatments with precise and instantaneous proppant-concentration control. Larger CT sizes are being used to enhance treatment rates, service longer horizontals, and provide additional weight or force at the end of the tubing for plug drillouts or manipulating service tools. The trend in longer and larger CT size is also driving the need to optimize the CT unit design to maintain operational efficiency and safety as well as meet Department of Transportation (DOT) regulations. This paper reviews these new CT techniques and trends being used to improve shale play developments with case histories. The successes demonstrated in the U.S. are now being targeted at shale-play developments in the eastern hemisphere and Latin America to meet their growing demand for clean and economical energy.