In the Bakken, pump-down perforating has been the preferred solution for multi-stage ‘plug & perf’ operations for years. However, when an operator in a Bakken, North Dakota field was faced with a restricted inner diameter, they turned to an unconventional solution of using e-line, tractor-based conveyance. The operation was a success and more such operations have been run. This paper will present the lessons learned from these operations, as well as discuss the applicability and efficiency gains of e-line, tractor-based conveyance. Best practice consideration will be proposed for future plug & perf operations in horizontal wells.
Several challenges led to the initial decision to select the tractor-conveyed solution. Poor road conditions made the logistics of heavy equipment difficult, and coupled with severe time constraints and strict budget considerations the e-line solution became the preferred choice. This decision enabled the operator to get this $9M asset on production in a timely manner.
A 3.6 in. patch was restricting the inner diameter of a 4½ in., 11.6# casing string. The operator needed to plug and perforate 26 zones horizontally from 21,740 ft up to 11,830 ft to get the well on-line quickly. Pumping the 4½ in. plug was not considered an option due to the risk of premature setting or pumping off plug and/or guns resulting in expensive and time consuming fishing operations. Coiled tubing would only be able to reach the first 16 zones leaving 10 zones imperforated. Rig operations would be too time consuming and costly.
The 26 run, e-line operation was completed in 14 days with no conveyance mis-runs or lost time but only one gun mis-fire. The well was brought on-line quickly and the logistical challenges easily overcome due to the lightweight nature of the e-line technology. As an added bonus the operation offered several HSE benefits stemming from the low footprint, reduced personnel requirements, and less heavy lifting.