Understanding the Hydraulic and Conductive Half Lengths in the Bakken/Three Forks Play – Coupling Sealed Wellbore Pressure Monitoring SWPM & Chow Pressure Group CPG

Abstract

Abstract In development of the Bakken/Three Forks play, it is crucial to obtain a strong understanding of not just the hydraulic fracture geometry, but also what portion of those hydraulic fractures are conductive. If both parameters and their interactions are not fully understood, then development of the play could be severely compromised due to unoptimized well spacing and completion design. This study represents a two-pronged approach to better understand this interaction. The first step was to perform a Sealed Wellbore Pressure Monitoring (SWPM) test to gain an understanding of hydraulic half-length (Haustveit. et al. 2020). Then, a conductive interference test was performed to utilize Chow Pressure Group (CPG) to understand the conductive half-length (Chu et al. 2018). This paper will address the results from these two tests and how they can be coupled together to optimize the unique relationship between well spacing and completion design to maximize the value in development of the Bakken/Three Forks play or any play both new and mature. The SWPM test was successfully completed on a nine well zipper frac operation consisting of two pads (four well pad/five well pad) where four Middle Bakken and five Three Forks wells were stimulated. The SWPM results provided insight into the hydraulic fracture geometry of the stimulation in multiple scenarios of vertical and lateral separation, as well as various amounts of offsetting depletion. The next step in the analysis was performing a CPG interference test on the five well zipper pad. The CPG results provided insight into not just the initial conductive geometry, but a three month follow up test also showed how the conductivity of the fractures rapidly degrade over time. By coupling the SWPM and CPG analysis together, an operator can learn where hydraulic fractures are growing and what portion of those fractures are conductive. This project design of coupled SWPM and CPG provided multiple learnings: Hydraulic fractures for a well in either the Middle Bakken or Three Forks grow through the Lower Bakken Shale and create large geometries in both the landing and staggered zone Hydraulic growth is faster and geometry larger growing towards modern completion parents versus vintage completion parents A relatively small portion of the hydraulic geometry is conductive, and although early time wells communicate through the Lower Bakken Shale, a 3-month interference test shows closure between the Three Forks and Middle Bakken. From these learnings, an optimized development is being developed for the Bakken/Three Forks play and a similar workflow can be applied to any play both new or mature to maximize value and returns for operators.