TX 75083-3836 U.S.A., fax 01-972-952-9435. AbstractBranches in Level 1 and 2 lateral extensions traditionally have offered limited access. Coiled tubing (CT) intervention was limited to the main hole only, and thus stimulation of main reservoir targets was not possible.A new system designed with a 2 1/8-in. outside diameter (OD) enables rigless intervention through the completion restriction. The system includes a reentry bottomhole assembly (BHA), which consists of a surface-controlled orienting tool and a controllable bent sub (CBS). The Discovery MLT * multilateral tool identifies the window of the selected lateral before attempting reentry, and confirms successful identification. The entry is visible at the surface through a software-displayed pressure log. The technique does not require a wired coiled tubing string; the corrosion-resistant reentry tool is operated solely by flow and is conveyed with standard CT equipment. As proved by the success of the new reentry tool in Upper Zakum field selective matrix stimulation and nitrogen kickoff operations detailed in this paper, the need to bullhead huge acid treatments that result in major openhole washouts has been eliminated. These washouts can cause both poor acid distribution and prevention of future access to the lateral for CT logging operations. This paper discusses the successful deployment of a selective multilateral entry tool that was utilized to access multilateral wells in Upper Zakum field, two case histories, and the method's potential in Upper Zakum field.The two case studies presented demonstrate the success of this system in reentering a desired lateral on the first attempt for matrix stimulation operations. Current developments that enlarge the scope of application to wellbore logging are under study.

No abstract

This paper was prepared for presentation at the 1998 Abu Dhabi International Petroleum Exhibition and Conference held in Abu Dhabi, 11-14 October 1998.

Background This prospective, double-blind, randomized, controlled trial compared the efficacy of two dexmedetomidine doses (50 and 100-μg) combined with levobupivacaine on sensory block duration in infraclavicular brachial plexus block. We hypothesized that perineural dexmedetomidine would extend sensory block duration dose-dependently. Methods The study included 60 patients aged 20 to 60 years of both sex with an ASA I/II undergoing forearm and hand surgery. The patients were randomly assigned into three equal groups (n = 20) for ultrasound-guided infraclavicular brachial plexus block. The L group received 35-mL 0.5% levobupivacaine plus normal saline, the LD50 group received 35-mL 0.5% levobupivacaine plus 50-μg dexmedetomidine, and the LD100 group received 35-mL 0.5% levobupivacaine plus 100-μg dexmedetomidine. Patients were investigated for onset and duration of sensory blockade, time to first postoperative rescue analgesia, and the total 24-h postoperative morphine requirement. Results The LD100 group had a longer sensory block duration (15.55 ± 1.1 h; 95% confidence interval (CI), 15.04–16.06) than the LD50 group (12.8 ± 1.2 h; 95% CI, 12.24–13.36 h) (p < 0.001) or the L group (9.95 ± 1.05 h; 95% CI, 9.46–10.44 h) (p < 0.001). The LD100 group took longer to request postoperative rescue analgesia and required fewer postoperative morphine doses than the LD50 and L groups (P < 0.001). Conclusions Sensory block duration was longer with perineural 100-μg dexmedetomidine as an adjunct to levobupivacaine than with 50-μg dexmedetomidine. Trial registration This study was approved by the Ethics Committee of Aswan University Hospital (approval number: aswu/125/4/17) (date of registration: 04/04/2017). Furthermore, the trial was retrospectively registered at ClinicalTrial.gov (NCT04729868) with a verification date of January 2021.

This paper was selected for presentaticm by an SPE Program Commntee fdbwing revbw 01 Information contained in an abstmct aubmNted by the author(s). Contents 01 the paper, as P-ntd, have not bean reviewed by the Society of Petrobm Engimaem and are eubject to cem'ectbn by tlw autl'mr(s). Tha mabfbl, as preeented, does not necesewliy reflect my p@ktn of the Society of Petroleum Engineers, its offb.sm, or membws, Papem presented at SPE meatings em WQW to publicatkm review by Editorial (%nmltha of the Socbty 0! Petweum Engirwers, PwmiiiOn to qis reetrkbd to a"~of Nt mom than 300 **, lllumt-a~~M h~. w~shW@~n~" of where and by whmn the paper is presented. Write Librarian, SPE, P.O. Sox SSSSSS,Richerdeon, TX cmepkwua =~ment ZWS&SBW, U.S.A., Telex, 1SS245 SPEUT. AEsmAm-