Many operators have increasingly moved toward cube development to avoid production impairment due to parent and child wells’ fracture-driven interactions (FDI). This cube development technique involves stimulating multiple wells in a section before bringing them online simultaneously or relatively close in time. This implies significant upfront investment to drill and complete in some cases 10’s of wells before producing a drop of hydrocarbon from them. Therefore, it becomes critical that the wells are completed optimally to be able to extract maximum resource from the reservoir. Multi-well stacked pad development renders itself as a 4D problem for completion optimization. Well spacing in horizontal and vertical direction and perforation spacing along the lateral being the 3 spatial dimensions, as well as the timing and sequencing of stages add the fourth dimension to the problem. Sensitizing for different sequencing scenarios in the modeling space before operational execution of the stimulation offers a cost-effective way to optimize production.
We explore the impact of hydraulic fracturing sequence and spacing on production from the group of stacked wells in a section of the Delaware Basin. A three-dimensional geomodel along with a discrete fracture network is utilized to model a complex hydraulic fracture system created for multiple treatment sequencing and spacing scenarios. Stress shadow from previously stimulated stages is seen to be a major driver in controlling the geometry of the fractures in the wells stimulated later and can be utilized to enhance reservoir contact. Finite element modeling shows the positive impact of the stress re-orientation resulting from previously stimulated stages. Hydraulic fractures confined by stress from outside wells show clear growth pattern into unstimulated sections of the reservoir, thus enhancing the production potential.
The stimulated reservoir volume and simulated production are used as key performance indicators (KPIs) for choosing the optimum sequencing and spacing strategy in this study, however the KPI can be changed to meet individual asset needs. This work aims to provide a workflow for modeling stacked well pad development and explores innovative approaches to sequence stimulation stages on wells in order to improve reservoir contact.