Fiber-Optic-Enabled Coiled Tubing Used To Access and Stimulate a Trilateral Oil Producer

Abstract

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 126730, ’First Worldwide Application of Fiber Optic Enabled Coiled Tubing With Multilateral Tool for Accessing and Stimulating a Trilateral Oil Producer, Saudia Arabia,’ by Ahmed Al-Zain, SPE, Rifat Said, SPE, Salman Gamber, and Saad Al-Driweesh, SPE, Saudi Aramco, and Khzam Al-Shahrani, SPE, and Jan Jacobsen, Schlumberger, originally prepared for the 2009 Kuwait International Petroleum Conference and Exhibition, Kuwait City, Kuwait, 14-16 December. Recent advances in coiled-tubing (CT) technology enable rigless interventions of complex wells while acquiring real-time downhole measurements. The fiber-optic-enabled CT (FOCT) provides combined services of data acquisition and running other CT tools required for well treatments. The fiber-optic telemetry system consists of a pump-through bottomhole assembly (BHA) with a casing-collar locator (CCL), pressure and temperature sensors, optical fibers inside CT, and a surface readout unit. Introduction Horizontal wells have become more commonplace in many Saudi Aramco fields. Recent advances in drilling and completion practices enable more-complex wells with various types and shapes, such as extended-reach wells, bilaterals, multilaterals, and maximum-reservoir-contact (MRC) wells, to be drilled. Benefits of drilling these wells include reduction in development and operating cost because of the smaller number of wells and improvement in reservoir performance and management. These complex wells are drilled for various reasons and many objectives, which may include but not be limited to increased production, enhanced reservoir characterization, improved sweep, maximized recovery, and to ensure efficient reservoir management. Background Well-A was drilled and completed as a trilateral openhole oil producer in 2008. The well was cased with 95/8-in. casing to the top of the producing reservoir at 6,220 ft measured depth (MD). An 8½-in. hole then was drilled directionally 3,000 ft inside the reservoir. A 7-in. liner was run and cemented at 9,220 ft MD. The main bore (L-0) then was drilled successfully to a total depth (TD) of 13,040 ft MD. After that, Lateral-1 (L-1) was drilled, after opening a casing window at 7,987 ft MD, to 11,350 ft MD. Following that, Lateral-2 (L-2) was drilled from a casing window at 6,422 ft MD to 9,786 ft MD. Figure 1 in the full-length paper shows trajectories of the laterals. The well was completed with 4½×3½×27/8-in. tubing and equipped with an electrical submersible pump (ESP) to produce the well. The ESP assembly has a bypass (Y-tool), that allows normal well interventions and other well surveys. The minimum inside diameter (ID) is 2.441 in. downhole in the tail pipe. After completion, the well was flowed for cleanup by the ESP, but it was found unable to flow, indicating severe formation damage.