New Stimulation Method Significantly Improves Hydrocarbon Recovery
Authors: Carpenter Chris 
Published: January 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 177061, “A New Stimulation Method To Significantly Improve Hydrocarbon Recovery by Use of Temporary Beneficial Changes in Stress Anisotropy,” by B.J. Lewis and J.B. Surjaatmadja, Halliburton, prepared for the 2015 SPE Latin American and Caribbean Petroleum Engineering Conference, Quito, Ecuador, 18–20 November. The paper has not been peer reviewed.

As a result of the creation of a hydraulic fracture, transient geomechanics forces are exerted on the formation, which modify the stress landscape near the wellbore and the fracture plane. It has been observed that the potential exists for temporary reversal in the minimum-stress direction, enabling a brief time interval in which a second hydraulic fracture can be created in a completely different direction. This provides hydraulic-fracturing connectivity to previously unattainable locations in the formation. This paper presents a computational validation of this multioriented hydraulic-fracturing (MOHF) process.

Overview of Pinpoint-Fracturing Techniques

Pinpoint fracturing, also known as pinpoint stimulation, is a general term used in the industry to refer to fracturing processes that specifically target individual treatment intervals in a multiple-interval completion. More than 20 different pinpoint-stimulation techniques have been developed for coiled-tubing- (CT) or drillpipe-deployed jetting tools. Although several mechanically actuated or explosive-perforation pinpoint methods have been developed, the most widely used pinpoint methods are hydrajet coupled stimulation procedures. This paper focuses only on the hydrajet methods and discusses how pinpoint fracturing can be applied to achieve an MOHF stimulation.

The length of the wellbore being treated per stage of the operation is usually much smaller than it is with conventional stimulation techniques. Conventional methods, either sliding-sleeve or plug-and-perforate, generally treat 15 m to more than 60 m of the wellbore at a time. In contrast, with pinpoint methods, only one fracture is being initiated by the hydrajets per treatment stage; therefore, more stages are generally used than with the plug-and- perforate method. The spacing between fractures is designed to be directly related to the expected drainage potential of each fracture and may also be influenced by the unique geological features in the area. This allows for a significant flexibility in terms of the treatment design. A summary of operational benefits of pinpoint stimulation is provided in the complete paper, but they include the following:

Large number of treatment intervals with only one trip into the well

Reduced time to complete each treatment interval

Reduced downtime between treatment intervals

Fracture placement designed for each individual fracture, rather than in large treatment intervals

Optimized stimulation-fluid system, pressure, and rate for every fracture

As with other processes, there are some drawbacks with pinpoint stimulation compared with conventional methods. If the stimulation treatment will be tubing-conveyed, a rig or hydraulic-workover (HWO) unit would be required on location. Most pinpoint methods also require two separate pumping sources to be available (one for the tubing flow and one for the annulus flow). Therefore, additional surface flow piping and valves are necessary; however, both pumping sources contribute to the total-treatment fluid-flow rate.