BREAKTHROUGH: Leading-Edge Cement Performs Strong In The Field
July 10, 2019
Author: Andy Jordan, Engineering Manager — Cementing
Evolving well construction practices in North America have focused on finding ways to decrease well costs. One general well design theme has been to minimize the number of casing strings to reduce material cost and time per well. However, in minimizing the number of sections, longer cemented sections are required which often creates a risk of lost circulation during cementing. To help mitigate this risk, lowering cement slurry density can reduce the hydrostatic pressures while placing cement — but systems to minimize lost circulation volumes in thief zones are also an important tool.
BJ Services’ IntegraGuard™ Star spacer systems have a long history of successfully reducing lost circulation. In laboratory experiments, the system can completely block fluid flow through high-permeability media, impressively stopping fluid losses into pea-size gravel.
But because many lost circulation scenarios involve fluid losses into fractures, we launched a new R&D initiative to evaluate the current IntegraGuard Star system capabilities and develop product enhancements.
The main test apparatus used was a slot tester. This is a pressurized fluid cell with interchangeable-width slot fixture. The slot has a parallel-sided, 1-in long opening, with widths up to 4 mm. Current IntegraGuard Star spacer systems could successfully seal a 1-mm slot with a differential pressure of 1,000 psi.
The challenge for the new system was to seal a 3-mm slot with differential pressures up to 3,000 psi. After extensive development and testing, a new system that incorporates a lost circulation material (LCM) was developed and branded IntegraGuard Star Plus 3K. This technology has produced breakthrough results in both the laboratory and the field, surpassing the capabilities of current spacers on the market. During laboratory testing, it exceeded expectations when it remarkably sealed a 3-mm slot up to 4,000 psi and a 4-mm slot up to 3,000 psi.
Field trials then began for IntegraGuard Star Plus 3K in March 2019, and the system has rapidly gained traction due to excellent results — 13 jobs in April and 25 jobs in May. In most field trials, the IntegraGuard Star Plus 3K system was able to establish cement returns to surface, which ensures regulatory compliance, zonal isolation and wellbore integrity. Additionally, one operator used the additive in a cement job redesign that eliminated the two-stage cementing in favor of a successful one-stage design—resulting in lower well costs and reduced well construction time.
For more information on IntegraGuard Star Plus 3K and this breakthrough enhancement, look for case histories on our website and come by our booth at URTeC (booth #156), July 22-25, 2019.