Electrical submersible pumping system (ESP) failures introduce many issues to operators and reservoirs. These issues can significantly increase operational expenditure (OPEX), especially in areas where it is challenging for workover rigs to operate or the rig cost is very high. In addition, production loss due to workover rig availability, mobilization, and climate challenges presents a major problem to operators to produce economically from this type of well.
Thru-tubing conveyed ESP (TTC ESP) using a pump-to-pump (P2P) connection allows wireline installation of a pump section followed by an additional tandem pump(s) installed on top of the first. Special profiles on the upper section of the lower tandem allow the shaft and housing engagement to match the lower section of the upper tandem pump. TTC with P2P helps reduce ESP installation time in areas where workover rigs cannot be mobilized during the winter season and the cost of intervention is very high. Several pump-to-pump systems were installed without issues and run in environments that were challenging for a conventional ESP.
The system was designed for economic production of recently fractured production wells by allowing low-cost replacement of the primary failure component, the ESP centrifugal pump. Current systems are too long to fit inside practical length wireline lubricators, so this new connection allows shorter pump sections to be stacked sequentially. Additional sections also allow higher head (increased number of stages) for deeper applications. This technology is currently achieving "blind" tandem pump installations at setting depths approaching 8,000 ft.