This paper introduces how GIS software and mathematical algorithms can be combined with the goal of efficiently placing well laterals in order to maximize drainage area of shale reservoirs.
Integer Linear Programming (ILP) and Geographic Information Systems (GIS) combined to solve the optimization problem of efficiently placing pads and laterals in order to maximize coverage of acreage positions while avoiding subsurface and surface constraints using multiple predefined drilling templates.
This methodology has been used to plan future infill development of Tecpetrol's Fortín de Piedra area in Vaca Muerta formation (Neuquén/Argentina). Results showed up to 84% coverage of drainage formation using 59 PADs with 230 new laterals of length 2.700 meters.
Real cases studies results show that this approach may provide an optimization opportunity in shale plays with many surface and subsurface constraints.
Fortín de Piedra area is in the center of the Neuquén basin, in Neuquén province, near the town of Añelo as shown in Figure 1. With an area of 248 km2, Tecpetrol operates this block with 100% of ownership. In 2017 Tecpetrol started an unconventional development plan targeted to fluid extraction in Vaca Muerta formation, one of the main sources of shale gas in the country (Biscayart et al, 2020). Up to date, Fortín de Piedra has become one of the key players for gas supply in the country, providing 14% of what is consumed in Argentina.
Tecpetrol's GIS1 Data Management Team is involved in the planning and representation of the drilling plan of the horizontal wells within the reservoir, also called unconventional development plan. Based on geoscientists’ well Pad2 designs, they locate Pads throughout the exploitation area while avoiding restrictions due to faults, drilled wells, or reservoir geometry.
This process was performed manually using a GIS software. Different developments plans are evaluated for a single area consuming up to two weeks of workday per analyzed scenario and with little chance to rapidly targeting the optimal distribution of Pads.
In 2019, Tecpetrol implemented a novel optimization algorithm based on Integer Linear Programming (ILP) that helped the company to optimize massive horizontal well developments while cutting processing times down to one day and targeting the optimal development plan in a couple of iterations.
