Assisted Field Development Planning Through Well Placement Automation

Abstract

This paper highlights a systematic and robust computer assisted reservoir simulation workflow to place oil producers and water injectors in the optimum areas of hydrocarbon reservoirs. The workflow offers modeling of several types of well pattern designs, including five-spot, fork-type, line-drive, and peripheral injection, allowing the multidisciplinary subsurface team to evaluate several development plans very efficiently. The workflow relies on automating the process of well placement across areas of interest with integration of static geological and dynamic simulation models. Opportunities within the reservoir are targeted using different well types, including vertical, horizontal, and multilaterals. This process incorporates different elements of well pattern designs, including well spacing, lateral length, azimuth, dogleg severity (DLS), and completions. For example, star-shaped offshore platforms with multiple wells are placed parallel to structure contours of the reservoir honoring oil-water contact (OWC) and gas-oil contact (GOC). Multiple zone lateral placement is achieved by positioning each lateral in targeted reservoir layers. This workflow was evaluated on a conceptual tight heterogeneous reservoir with several development strategies, including star-shaped platforms with peripheral water injection. Each platform consisted of several dual and trilaterals targeting different horizons of the reservoir. The development plans were evaluated through numerical simulation and well performance was analyzed. The analysis indicated considerable improvement in field cumulative oil production and ultimate recovery. Different field development plans (FDPs) are generated in a few minutes instead of months when using traditional workflows. Overall, a 90% reduction in time has been observed in this work. The significance of this workflow increases when preparing FDPs for geologically heterogeneous reservoirs with complex well designs and challenging operational constraints. The results achieved using this workflow demonstrate a unique opportunity in creating a variety of well designs automatically to target huge and complex reservoirs under a secondary drive production mechanism. This workflow is not only valuable in early phase field development planning, but also applicable in designing multiple sidetracks and reentry wells as part of the infill drilling program in mature fields.