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