MINI-FRAC / DIAGNOSTIC FRACTURE INJECTION TEST (DFIT)

BGES is experienced in performing mini-fracs/DFITs in both open-hole and cased-hole, with and without flowback.

A critical component of determining caprock integrity is the determination of in-situ stresses. Mini-fracs and DFIT’s are reliable and cost-effective techniques for indirectly measuring the formation’s minimum in-situ stress.

During a mini-frac, test fluid is pumped in a short pulse into the reservoir to create a small fracture that cuts through near- wellbore damage to establish communication with the true formation. Hydraulic fractures naturally follow the path of least resistance, thus propagating perpendicular to the formation’s minimum principal stress. After the fracture is opened, the pumps are shut down. As the downhole pressure declines, test fluid leaks off into the formation and the induced fracture closes. Pressure data can be analyzed to determine when the fracture closes. The pressure at which a hydraulic fracture closes is considered to be equivalent to the smallest principal in-situ stress of the formation.

To detect when the fracture closure occurs, BGES believes that a single unique closure event should satisfy multiple diagnostic plots or methods. Therefore, a combination of different analytical methods is used in concert to arrive at a consistent interpretation of fracture closure.

These tests can be done in open- or cased-hole completions. Open-hole tests have the risk of being impacted by packer-induced stress, but if done properly, its results can be used to estimate the maximum horizontal stress.

Applications

The minimum in-situ stress is an important parameter for many applications, especially for SAGD, CSS, Water/polymer flood operations, where the caprock’s minimum in-situ stress governs the maximum operating injection pressure in order to avoid fracturing the caprock. For any new or expansion projects, mini-fracs/DFITs are mandatory under AER’s requirements. DFITs are also performed to obtain information for fracture treatment design for shale oil/gas production.

Features & Benefits

Test program is customizable depending on customer needs. Field execution is handled by specially-trained technicians and managed by an experienced Professional Engineer. Real-time closure confirmation can be conducted before ending a test to ensure that useful data is obtained. As a key deliverable, BGES can provide a comprehensive report with detailed analyses and transparent interpretation to help streamline customers’ regulatory application.

Operations

BGES is capable of performing both open-hole and cased-hole mini-fracs, with and without flowback. Steady and constant injection of test fluid is accomplished through the use of our advanced DCS-controlled injection unit. In order to ensure the accuracy and quality of data obtained, multiple points of high-precision measurements are taken at the wellhead and downhole with backups. Test data can be viewed in real-time through the internet as it is acquired in the field.

Integration of Services

From wellsite core collection, geotechnical lab testing, cased-hole logging, reservoir and caprock injection testing, data analyses, project management, regulatory reporting, to computer simulation and numerical modelling, our comprehensive and customizable service model offers maximum flexibility for our clients.