External Casing Packers (ECP) successfully isolated thief zones, enabling two-stage cementing operations onshore Argentina
Fractures or highly permeable formations can cause loss zones during drilling. This can impair the circulation of cement and jeopardize the wellbore. The cost of remedial cementing, production delays, and drilling problems after partial or total losses is millions of dollars per year.
To limit the potential effect of lost circulation, the operators commonly lessen the density of the cement slurry, constrain the friction pressure while pumping, or resort to stage cementing operations. This third alternative consists in combining open-hole annulus packers with stage collars to avoid the thief zone.
An operator in Argentina (Anticlinal Grande field) conducted a multiple-well drilling campaign. With a requirement of external casing packers (ECP) to perform 2-stage cementing operations. They encountered frequent loss zones while drilling and needed a cost-effective solution to secure the annulus integrity and cement successfully back to the surface.
Selecting Saltel Xpandable Steel external casing packer
Schlumberger recommended Saltel Xpandable Steel Packers. It was necessary to set the packers either in an open hole or in deviated and under-gauged holes, so that they could withstand tough RIH conditions. The possibility of rotating and put weight on the packer during RIH was also essential.
In stage cementing applications, Saltel’s Xpandable external casing packer is ideal.
We installed 10 Xpandable external casing packers 5.5in as annulus barriers in a 9.2in open hole. In order to isolate the thieves’ zones and allow a second cement stage above them. The maximum depth of the wells was 8,200 ft [2,500 m], and the setting depth goes from 1,968 to 5,577 ft [600 to 1,700 m].
The cementing campaign recorded 100% success with Saltel Xpandable Steel Packers. The 10 packers isolated the troublesome lost circulation zones and allowed resuming cementing operations. The cement could be pumped back to the surface through a stage collar above the ECP.