Multilaterals: An Overview and Issues Involved in Adopting This Technology

Abstract

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

A Novel Technique to Acidize Multilateral Open Hole ER Horizontal Wells Drilled in Carbonate Formations

“…5,6 This technology gap is significant for multilateral ER wells. 7,8 Previously, access to individual branches was not possible, 9,10 which prevented effective stimulation and production logging of individual laterals. Acid had to be bullheaded down wellbore tubulars or coiled tubing with the end of pipe near the lateral entrance.…”

Numerical modeling of the stability of horizontal multidrain oil wells

“…Multilateral wellbores -separate drain holes or branches, drilled from a single primary borehole (Fraija et al, 2002) -offer the potential for substantial improvement in well economics (Vij et al, 1998). They potentially reduce total capital expenditures and development costs as well as operational expenses by decreasing the number of the required wells (Jordan et al, 2002).…”

“…This technology can help us to produce multiple reservoirs, enhance drainage pattern, increase fracture exposure, reduce environmental damage, reduce overburden and surface facilities costs, decrease impacts of water/gas coning, etc. (Vij et al, 1998;Garrouch et al, 2004). The current costs of drilling and completion of multidrain wells are more than several million dollars for each branch (Garrouch et al, 2004).…”

A Rigorous Composite-IPR Model for Multilateral Wells

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