The water cut on an online gas producing well had been steadily increasing. Post shutdown the well became steadily more difficult to bring online. As such a CT (Coiled Tubing) intervention was undertaken to determine the location of the water production. On a previous intervention using the RtC (Real Time Coil) system, a PLT (Production Logging Tool) string found the location of water production. Subsequent attempts to bring the well back online through gas lifting then proved unsuccessful due to the volume of water being produced. The goal was then set to isolate the water producing zone and bring the well back online once more. This was to be achieved within the following conditions:
Altus Intervention, working in conjunction with Weatherford, suggested placing a CT straddle to isolate the water producing zone. Using a Weatherford packer system, Altus Intervention would deploy 2-7/8” CT to make up the straddle.
Details of the 2-7/8” CT are as follows:
|CT Grade||QT - 1000|
To ensure the system could be deployed whilst adhering to API 16ST regulations, an involved Pressure Control Equipment stack up was required.
The required length of CT was mobilised offshore and positioned on the platform. The CT&P equipment spread was then also mobilised and rigged up. With the equipment rigged up and tested the following runs were undertaken:
The 1400ft straddle was successfully deployed with minimal downtime and no HSE incidents. The well was brought back online and production recommenced with a much reduced water cut.