Impulse testing using a simple drillstem testing (DST) or tubing-conveyed perforating (TCP) string is reinvigorated by employing a bidirectional wireless acoustic telemetry system. Paired with enhanced-functionality downhole test tools, the innovative approach reduces the cost of testing while providing critical data for completion design, reservoir monitoring and electric submersible pump (ESP) sizing.
Over 46% of all the reported premature pump failures today are associated with incorrect equipment selection and pump sizing. It is mainly due to a lack of reliable reservoir information and especially in new wells without any historical production data (Vandevier, 2010).Operating the pump outside its specified range due to incorrect sizing can cause either a severe downthrust or upthrust condition that results in premature wear of the pump stages and reduces the expected life. It is mainly associated with incorrect pump sizing due to a lack of reliable reservoir information. The oil industry has long sought improvements in performing reservoir characterisation and acquiring dynamic reservoir and well data necessary for ESP sizing, especially in new wells without historical production data. The proposed new methodology and a unique impulse testing technique allow acquiring reservoir data for proper pump sizing.
The impulse testing is not a new concept that allows testing the wells using a simple DST or TCP strings with no flow of hydrocarbon at the surface. This allows the cost to be reduced in comparison with conventional DST operations or any other testing methods.
A new impulse testing technique uses bi-directional wireless acoustic telemetry system to acquire real-time bottom hole pressure data and interface with remote-controllable new-generation downhole tools, such as a tester valve, circulating valve, firing head, or fluid sampler, to issue commands and verify tool status. The acquired data credibly represent reservoir pressure, fluid properties, and well inflow performance that can be used for proper pump sizing.