Multilaterals, an upcoming technology, offers the potential for substantial improvement in well economics. Integrated efforts of service companies and operators have made this upcoming technology a viable completion technique. The issues like maturing reservoirs, many of the existing wells with uneconomical- to-recover results in place and increasingly expensive offshore structure and drilling operations, are addressed in a very positive way by recent advances in the ML Technology. This technology allows to have same magnitude of reservoir exposure with lesser number of wells on surface platform. Also, there is a potential for reducing water-gas Coning and improved recovery of oil. Overview of multilateral technology, its applications and limitations have been covered in the paper. Being comparatively a new technology, higher costs and risks involved during drilling/ completion/servicing would need to be kept in view while deciding to go in for multilaterals. Modelling of multilaterals may be complex for particular configurations, because of likely interplay between reservoir performance and friction losses and pressure continuity in the well bore. Special simulation packages (coupling fluid flow in the reservoir and laterals) may be required for the purpose. Studies so far undertaken in the industry on this issue have been discussed. Multilateral system offered by various service companies, from existing and new wells, have been discussed, covering issues like isolation between laterals, flow control, re-entry access/interventions, dual string completions. Worldwide experience on economics of multilaterals has also been covered. Reservoir screening criteria provided in the paper may be used as guidelines for selecting reservoirs for possible applications of multilateral technology. Multi-disciplinary approach would be required for effective implementation of this technology. P. 109

Copy'lghl 1996, %ciety of PetroleumEngineers,Inc, llds paperwas prepsred fw presentation at the f998 SPE India Oil and Gas Conferenceand Exhibition heldin New Oelhi.Ma, 17-19 February1998. 7hk psper was selected fcf presentalkm Fy an SPE Prcgram Committee foflowing review of information cc+slsined in an abstract submitted by [he author(s). Cordenk of the paper, as prssenled, have not been rekiewedby the society of Petroleum Engineers and are subject to mrrecficm by the author(s). The material, as presented, dc=ss not necessarily reflect any pnsillon of fhe society of Petroleum Engineers, its officers, of members. Papers presented a! S!% meetings are subject 10 publicationreview by EdiloriaT Committees of the Stiely "N Petroleum Enginee"m. EfeCT67KrepWiEfbn, distribution, or storage of any psrf of this psper for ccmmerctsl purposes withwt Ihe wniten cunaent of the Scwlely of Petroleum Engineers is prohibited. Permission 10 reproduce In prfnl Is restricted to an abstract of not more than 300 words; illustrations msy not be copied. The abstract must contsln conspicuous acknovdedgmenl of Mere and by whom the psper was presented Wrtte Librarian, SPE, PO. Box 833S36, Richardson, 7X 75083-3836, U.S,A,. fsx 01-972-952-9435. AbstractMultilateral, an upcoming technology, offers the potential for substantial improvement in well economics, Integrated efforts of service companies and operators have made this upcoming technology a viable completion technique.The issues like maturing rewrVoir6, ninny of the existing wells with uneconomical-to-recover results in place and increasingly expensive ofTshore structure and drilling operations, are addressed in a very positive way by recent advances in the ML Technology. This technology aIIows to have same magnitude of reservoir exposure whh lesser number of wells on surfacel platform.Also, there is a potential for reducing water-gas coning and improved recovery of oil.Oveiview of multilateral technology, its applications and limitations have been covered in the paper. Being comparatively a new technology, higher costs and risks involved during driIIing/ compIetiorJ servicing would need to be kept in view) while deciding to go in for multilateral.Modelling of multilateral may be compIex for particular conf@rations, because of likeIy interplay between reservoir performance and fiction losses and pressure continuity in the weI1 bore. Special simulation packages (coupling fluid flow in the reservoir and laterals) may be required for the purpose. Studies so far undertaken in ihe industry on this issue have been discussed.MuMlateral system offered by various service companies, from existing and new weIIs, have been discussed, covering issues Iike isolation between laterals, flow control, re-entry access/interventions, dual string completions. experience on economics of multilateral has covered.Worldwide also been 109 .Reservoir screening criteria provided in the paper may be used as guidelines for selecting reservoirs for possl%le applications of multilateral technology.Multi-disciplinary a...