Technology Trial Review: Selective Coiled Tubing Re-Entry of Two Open Hole Multilateral Wells Using Intelligent Electromechanical Arm

Abstract

Abstract A maximum reservoir contact (MRC) well, by definition, is a single or a multilateral horizontal well with more than five km of total contact with the reservoir rock. Planning of these wells requires extensive modeling studies to optimize total length, placement and configuration of branches. The main objective behind the MRC well concept was to improve individual well productivity and hence reduce the unit development cost and to better develop hydrocarbon assets. In fact, oil fields developed using MRC wells shows significant improvements in those wells performance in terms of increased PI, lower drawdown, and significantly delaying water and gas conning. A major challenge that faces production engineers in their daily operations is identifying and accessing laterals windows in those MRC multilateral wells, in order to preform rigless downhole sensing and intervention jobs (logging, stimulation, etc.). This challenge varies in difficulty based on the technology advancement of multilaterals (TAML) level, for example in TAML level 2 wells (cased mainbore) metal logging tools such as casing collar locator can be used to identify and confirm the access of laterals, while this of course is not an option in TAML Level 1 multilateral wells (open hole mainbore and lateral). Another reason selective re-entry of TAML Level 1 is considered very difficult is due to the shape and quality of the wellbore near the junction (window), post drilling and after distortion of hydrocarbon flow. This paper presents an intelligent electromechanical tool, jointly developed to address this issue. The tool consists of a sensing package that can identify and locate the depth and orientation of the lateral window using US and EM sensors, and an electromechanical arm that can be easily rotated and actuated with a wide range of angle, to lead and steer the bottom-hole assembly into the required lateral. This paper also presents the discoveries, challenges, and results of testing this intelligent tool in two TAML Level 1 multilateral oil producers, one fishbone well with a mainbore and six open hole laterals branching from it (shut in conditions) (Mohannad Abdelaziz, 2016), and the other is an open hole well mainbore with a lateral branching from it (shut in, flowing conditions). In Both trials the tool was successfully used to guide a production logging tool into different wells laterals.