Case History – World's First Slim Open Hole Smart MRC Wells

Abstract

Smart Maximum Reservoir Contact (MRC) wells have been successfully utilized extensively across Saudi Aramco to increase reservoir contact, well productivity and total oil recovery. This concept has primarily been used in newly drilled wells. It requires larger than conventional hole and casing sizes to achieve the dimensions required for the Intelligent Well System. Converting an existing well to an MRC poses a new challenge. This paper presents a case history of two old existing dead wells in Saudi Aramco that were successfully converted into the first Slim Open Hole MRC Wells in the world. The two wells were originally drilled as vertical producing wells with 7" 23# liner set above the top of the target zone and extending to surface. To access more reserves from the field, the decision was made to sidetrack the wells to a new location and drill an MRC wells to achieve maximum productivity from those wells. The wells were planned to be a three lateral wells with a total of 12,000' of reservoir contact in each well. To maximize the long term productivity of the wells, it was decided to run Intelligent Well Systems that enables remote monitoring and control of each lateral throughout the life of the two wells. The final success of these converted slim open hole smart MRC wells are supported by more than expected production gain. Introduction The industry faces a general challenge in meeting the well production objectives when a producing field is mature. To reduce well cost and maximize oil recovery, sidetrack is obviously effective approach. However the conventional method entails a significant wellbore ID reduction when curve section is isolated with conventional cemented liner. In addition, delivering smooth wellbore for high cost smart completion equipment was also a very pronounced critical concern. To meet these challenges, three current cutting-edge technologies are adopted and put to use.The first is the 5–1/2" x 7" cemented expandable liner for the effective zonal isolation of the curved section before the reservoir target entry. This technology offers a minimum (10%) hole reduction. Saudi Aramco is at the fore front of utilizing this technology and gained significant field experiences and most important of all, demonstrated a great value added for substantial production gain over the last several years of field applications 1 - 2.The second is the modified rotary steerable system that enables directionally drilling smooth 5–1/2" laterals with full LWD capability. The technology has been shown to substantially improve bit performance, in fact setting many world records recently in Saudi Arabia 1.The third is the slim hole smart completion equipment that functions inside 5–1/2" open hole. This includes open hole packers with feed-through control lines and downhole ICV (interval control valve) in addition to downhole permanent pressure & temperature gauges for reservoir monitoring as well as flow control of laterals at surface. The slim open hole packer was previously utilized successfully in a similar well application to pass through 5–1/2" expandable liner (for zonal isolation of the curved section) and set as compartment tool in 5–1/2" open hole in reservoir for passive inflow control 3.