Resource plays are constantly challenged with ways to reduce costs and cycle times. The Mississippian carbonate reservoir offers thickness and rock strength, together with stacked pay conducive to multilateral techniques and their inherent cost savings. A multi-disciplinary team has drilled and completed over 25 multilaterals of various configurations, validating the mechanical feasibility, along with associated cost and production benefits. This paper presents details on operational techniques needed to successfully build the multilateral wellbore, pros and cons associated with the different concepts and some of the initial cost and production results.
Open-hole sidetracks along with cased-hole whipstocks are used to initiate the multilaterals. The reservoir requires stimulation, which necessitates running a packer and sleeve system typically run on a 4-1/2″ liner. After stimulation, the casing is cut-off in the open hole leaving each leg open to the multilateral junction to produce into a common wellbore.
Over 25 multilaterals have been completed with 100% mechanical success. Directional techniques and completion systems make this a viable alternative to single well laterals enabling cost reductions on a field-wide development. These cost reductions provide needed benefit, especially in a reduced oil price environment.
SandRidge Energy, Inc. started work in the Mississippian play in Oklahoma & Kansas beginning in 2009. The use of horizontal drilling techniques in this mature carbonate reservoir together with an aggressive infrastructure strategy has led to over 1,200 horizontal wells being drilled. The multilateral program is ongoing, so additional production information and results will be shared as it becomes available to the public.