Customer challenges
- Expro was approached by a national oil company to perforate 9 5/8" casing. This required 7" TCP guns
- The customer had low consolidated formation with expected sand production in the direction of a maximum stress of (220 degrees from true north) within the nearly vertical wellbore. To limit the sand production, the customer wanted to shoot 1-180 degree TCP guns perpendicular (90º) to maximum stress to save the expense of gravel packing after perforating
- Also, they wanted to use Dynamic Underbalance (DUB) to properly clean perforations, reduce skin, and maximise production. To prevent perforation tunnel collapse, however, the amount of DUB required was very low (-200 psi). In order to achieve this, the wellbore was slightly overbalanced but the net DUB was negative
- The customer was looking for a minimum production of 2500 bpd
Expro Excellence
- Traditional orienting applications are limited to highly deviated or horizontal wellbores. In vertical wells where the orientation is typically limited to centralisation or decentralisation of perforating guns, a non-conventional engineering solution was required
- Expro proposed a solution utilising a conventional TCP string with 3rd party gyro and UBHO sub - this aligns the top shot with phasing accuracy less than 1° in the given well inclination. Competitor solutions were limited to 30º degree well inclination with ≥ 5º accuracy at three times more cost than conventional TCP cost
- Modelling using SPOT software proved that a minimum 6 spf at 0-180 degrees were required in order to meet the customer's desired production rates
Value to client
- Expro was able to successfully provide an engineered solution on time and under budget
- Customer's production rates exceeded expectations
- DUB guns shot in the required direction with ± 0.9º error eliminating sand production issues and ensuring cost savings in the region of $600k on competitor offerings
- Expro's surface well test report showed zero sand production during well uploading and production
