CST Case Study: Cement squeeze job using CST as base

Objectives

A major operator in the Gulf of Mexico aimed to address severe losses encountered while drilling a 20” section below a 16” casing using 11.3 ppg mud.

The plan was to shut off the loss zone by performing a squeeze cement job, utilizing a 2 ½” Cement Support Tool (CST) as the base.

The expected loss zone was located between the 16” casing shoe at 11,585 ft and 11,615 ft. The CST was to be deployed in the 20” open hole at 11,615 ft before the cement job.

Results

A balanced cement plug with 16.4 ppg cement was successfully set from the CST up to 10,723 ft. Subsequently, 90 bbl of cement was squeezed into the loss zone using the CST as the base.

After waiting for the cement to harden, the cement plug was drilled out. Firm cement was tagged at 11,145 ft, and the bottom of the cement was found at 11,614 ft, only 1 ft from the CST setting depth.

No cement was found below the CST, indicating that the loss zone was successfully shut off. The cement and CST were then drilled out using a PDC bit.

CST 2"

CST 2"

CST 2 ½"

CST 2 ½"

CST 4 "

2 ⅜"

Case study

Cement squeeze job using CST as base

Objectives

Results

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