It is a well-established principle that rock properties affect fracture geometry. This paper investigates the relationships between fracture responses observed during completion operations and rock properties that are obtained during the drilling of a well. It will also attempt to quantify the benefits of designing completions based on these rock properties.
Four pairs of wells adjacent to one another are included the study. Each pair of wells includes one well with a completion design based on the operator's baseline guidelines, and one well with the perforation depths and stage boundaries selected from rock strength information derived from drilling data. The fracture treatment pressure responses are correlated to the rock properties, and the two completion methodologies are compared to determine whether there is an operational or production benefit to this completion methodology.
The results of the study show a clear and distinctive difference between treatment responses in wells whose completions are based upon drilling-derived rock properties, and those that did not. The most striking of these differences is that instantaneous shut-in pressures were higher in wells where completion stages and perforation depths were selected based on rock properties, without corresponding increases in average treatment pressures. This is likely an indication of improved fracture containment (higher net pressures) which would be expected with an equitable fluid distribution among perforation clusters. Further to this, the analysis allowed for the identification of rock parameters associated with increased risk of excessive height growth which is independent of the completion methodology used. Production comparisons will be included to support the findings.
The result of this work is a clear path forward to improving future wells by understanding how rock properties and completion design are related to fracture height growth. This allows for a re-evaluation of future drilling targets and the modification of treatment designs to maintain the maximum amount of fracture energy within the target zone. It will also help to provide further evidence that completions can be improved through the optimized placements of stage boundaries and perforation clusters.
This paper will present a new analytical workflow that combines the use of drilling-derived rock properties and fracture treatment responses to gain important insights and drive future decisions for both the drilling and completion processes.