Eagle Ford Well Spacing: A Methodology to Integrate, Analyze, and Visualize Multisource Data in Solving a Complex Value-Focused Problem

Abstract

Determination of proper well spacing is a key factor in successful resource play development. The objective is to optimize the spacing between wells that effectively stimulates the reservoir rock volume, increases overall recoveries and minimizes interference between wells. Recent work by Pioneer Natural Resources, Inc. (PXD) to optimize well spacing along the Eagle Ford Shale trend has resulted in reduced lateral spacing as well as vertical staggering of wells within the reservoir interval. Numerous tools are used to aid the determination of well spacing across the play, and it is critical to integrate data from all the tools available when establishing a spacing recommendation. The workflow presented is used to establish spacing recommendations through integration and analysis of multi-source data collected during the lifecycle of an unconventional resource play.The well spacing toolkit includes data collected from multiple disciplines in the asset. Microseismic data is integrated with 3D seismic data and fracture models to derive stimulated rock volumes. RA tracer and chemical fluid tracer data collected during well stimulation provide information on propped fracture length and height and inter-well communication, respectively. Pressure data recorded during well stimulation and interference tests performed after stimulation are used to help understand changes in well communication over time. Oil and gas geochemistry data from wells drilled in multiple stratigraphic intervals are used to provide insight on fracture height growth.The ability to integrate and analyze multi-source data is essential when establishing a recommendation on a complex problem such as proper well spacing; the workflow presented allows for the manipulation and visualization of these data in 4D that can be interpreted and edited by multiple users.

Physical Models for Inter-Well Interference in Shale Reservoirs: Relative Impacts of Fracture Hits and Matrix Permeability

“…During the pressure test, all wells are first shut in to build up pressure. After a certain period, some wells are brought back on production in sequence while bottomhole pressure (BHP) or wellhead pressure of the shut-in well is measured (Lindner and Bello 2015). If the well interference occurs through highconductive connecting fractures, the shut-in well(s) will experience an instantaneous pressure drop.…”

“…Figure 2 only presents three possible causes of well interference in a single reservoir layer: (a) interference through matrix permeability; (b) interference through connecting hydraulic fractures; and (c) interference through natural fractures, or a combination of mechanisms (a)-(c). In addition, well interference can occur across different reservoir layers (Lindner and Bello 2015). Any well interference through the matrix in shale formations with ultralow permeability is more limited than that occurring through connecting fractures (Awada et al 2016).…”