Operator needs to improve declining injection rate in dual-lateral injector well

A Middle East operator had drilled and completed a dual-lateral water injector well to provide pressure support and enhance reservoir sweep efficiency. The well had two openhole laterals of more than 4,000 ft [1,219 m] each. Initial injection rates were 5,000 bbl/d with 2,800 psi [19 MPa] of wellhead pressure, but injection gradually declined to 2,000 bbl/d (maintaining the same injection pressure). The operator decided to acidize the two laterals with the aim of restoring the well to its initial injection rate of 5,000 bbl/d.

Original combination of technologies provides unprecedented guidance for advanced stimulation strategy

Schlumberger recommended performing the treatment using the Discovery MLT system to locate the entrance of each lateral. Once accessed, each lateral was immediately identified using the ACTive GR tool by comparing real-time data with the operator's reference logs. To optimize stimulation fluid placement, the operator needed accurate data about the injection contribution to each lateral as well as the distribution of intake and tight zones along both openhole sections. To this end, the ACTive DFLO CT real-time flow measurement tool was used to profile flow along the entire sections of interest.

Once it was determined that most of the injected water was flowing to the main bore, Schlumberger engineers worked with the operator to adjust the pumping sequence along each lateral and maximize acid coverage to obtain a more uniform intake.

Results far exceed target injection rate

The comparison between the pre- and poststimulation ACTive Q service profiles showed a significant improvement in coverage along the two laterals and a more balanced injection distribution between them. As a result of this intervention, the well's injection rate increased to 14,000 bbl/d, an impressive 600% improvement over the prestimulation level. These results also substantially exceeded the target injection rate of 5,000 bbl/d.