Use of Numerical Modeling to Optimize Completion Design of Horizontal Multistage Fractured Well in Unconventional Source Rock under Uncertainty Parameters

Abstract

The development of unconventional resources is capital intensive and challenging where operators spend a large amount of resources to maximize value. This is a direct result of completing thousands of wells with multistage fracturing. The optimization of well completion to enhance hydrocarbon recovery will help to reduce development costs and enhance project economics under the uncertainty parameters: geological, engineering, and economic. The paper demonstrates a novel workflow as an effective way to optimize completion design by integrating advanced multi-stage fracture modeling with reservoir simulation in an unconventional resource play. This work shows an integrated workflow using a compositional dynamic simulation study for gas condensate well. The complexity of gas flow physics in both nano-darcy reservoir as well as hydraulically fractured Stimulated Rock Volume (SRV) are considered. The physics include gas desorption, pressure dependent permeability, non-Darcy flow and gas condensate fluid behavior. The workflow includes QA/QC of the geologic model with a fine model resolution to map the hydraulic fractures. Long-term flow back data is used to calibrate the simulation model using history matching regions following the analytical trilinear model. After achieving a reasonable history matching, a detailed uncertainty assessment was performed to estimate P10, P50 and P90 of the well's EUR (Estimated Ultimate Recovery) using Proxy modeling workflow. Uncertainty parameters include hydraulic fracture half-length, SRV permeability, dew point pressure, under-saturated desorption pressure, rock compaction trend, etc. Finally, what-if scenarios were performed to assess the impact of cluster spacing, fracture height, horizontal well length and minimum well head pressure (WHP) on the well's EUR. The results of this work illustrates the workflow used to optimize well completion design including the number of stages along the lateral, length of the lateral, treatment sizes and how it impacts well performance as well to support management decision making.