THREE-MILE LATERAL CLEAN-OUT AND TOE PERFORATION WITH THE WELL CLEANER® REVERSE CIRCULATING BIT

Background

A well located in Bakken shale in North Dakota was drilled to over 26,000 ft with an extreme-length, three-mile lateral. These wells had been drilled with the objective of increasing production, but the operator was having difficulty achieving enough flow rate to initiate the toe stage of the lateral. The well was dirty and needed to be cleaned and gauged prior to perforation.

Both coiled tubing (CT) and pump down methods were attempted previously and failed. CT could not reach the extreme lateral length without buckling, and service providers could not achieve high enough rates to reach the toe with pump down solutions. It would be weeks before stick pipe arrived, which, upon arrival, would take additional time to successfully complete the operation.

Owing to prior similar successes in long laterals, Welltec® was approached to clean and gauge the well and perforate the toe.

OPERATION

It was decided that Welltec’s Well Cleaner® Reverse Circulating Bit (RCB) tool would be run with the Well Tractor® to clean and gauge the toe stage. The Well Tractor® would then be used to convey the perforating string through the extended lateral.

During the first run, the Well Tractor conveyed the toolstring 14796 ft to the toe stage of the lateral. The Well Tractor® and Well Cleaner® RCB were used in tandem to clean and gauge the well and retrieve approximately 40 ft of debris from the toe of the well.

For the second run, the Well Tractor® conveyed the perforating string to the target depth in the toe and prepared the well for future frac operations. The stage was successfully perforated, enabling the client to pump down and frac for the remainder of the well. During this run, the Well Tractor® was used to convey the perforating guns for 14750 ft across the lateral.

ACHIEVEMENTS

Welltec® succeeded in reaching, cleaning, and perforating this extreme lateral in North Dakota where prior attempts by heavier, costlier methods failed. The Well Cleaner® RCB tool provided the client with debris samples from the toe stage, and the Well Tractor® successfully conveyed the perforating string through the entire extent of the lateral. The operation took only a day and a half. CT would have taken three or four days, and stick pipe, once it arrived, would have taken at least a week. Beyond saving crucial time in completing the operation successfully, Welltec’s wireline solution provided significant cost savings for the client as well.

After the success of this operation, the client called on Welltec® to reach the toe stage of an extended lateral on another well the following week.