Coiled Tubing & Pumping
1400ft Straddle Brings Well Back Online
Altus Intervention successfully deploys 1400ft straddle to bring well back online
1400ft 2.875” Coiled Tubing straddle successfully set
Water producing zone successfully isolated and well life extended
Collaborative approach with Weatherford International
Challenge
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:
- Limited personnel due to bed space restrictions
- Limited deck space due to platform size
- 30Te crane limit
Solution
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 OD | 2.875" |
| CT Wall | 0.156" |
| Weight | 4.534lb/ft |
| 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.
Results
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:
- RIH to mill out landing nipple to allow access for lower straddle packer
- Correlation run including tubing end locator
- RIH to set lower straddle packer
- RIH to sting into lower packer, set upper packer and straddle
- RIH to sting into upper packer and burst straddle burst disks
- RIH to gas lift well onto production
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.