Hydraulic fracturing of horizontal wells in shale gas reservoirs is now an established, commercially successful technique. The evolution of the completion technique has reached the point that numerous stimulation stages through multiple perforation clusters in wellbores with some form of annular isolation is now an accepted practice. The objective is to place multiple closely spaced hydraulic fractures. This has proven to be a viable development strategy for many shale reservoirs in North America.

To further enhance the recovery factor in these ultra low permeability reservoirs simultaneously hydraulically fracturing of adjacent wellbore is increasingly being tested. Most of the time this is performed in horizontal wellbores paralleling each other. The goal is to create hydraulic fractures more closely spaced than can be achieved from a single wellbore. When real time microseismic monitoring of the stimulation treatments is incorporated changes can be made "On-the-Fly" to improve the effective stimulated reservoir volume.

Continental Resources has employed simultaneous hydraulic fracturing as a development strategy for their Woodford Shale acreage in the Arkoma Basin of Eastern Oklahoma. To monitor the effectiveness of the stimulations geophones have been deployed into horizontal wellbores to record microseismic events when offsetting vertical wellbores are unavailable. Cased hole sonic logs have also been run to quantify cement bond quality, estimate stress variation along the lateral, and to pick optimum perforating points.

This paper reviews the methodology employed in the completion design and process. The impact of the simultaneous stimulations and geologic structure on the fracture geometry are shown as well as the impact on well productivity.

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