Solution prevents lost circulation and fluid influx into unset cement

Overview

Cementing operations in formations with narrow pore pressure and fracture gradients pose significant challenges. These environments increase the risk of lost circulation and fluid influx into unset cement, which can compromise zonal isolation by creating channels in the cement barrier. Achieving optimal cement placement is essential to maintaining long-term wellbore integrity.

Challenge

Halliburton recommended a tailored cementing strategy using the Tuned® Defense™ cement spacer combined with BridgeMaker™ II lost circulation material (LCM) to prepare the annulus and reduce the risk of lost circulation.

A heavyweight cement slurry was formulated with Micromax additive and latex to deliver sufficient overbalance in the zone of interest, minimize permeability, and achieve optimum cement transition time. To further improve bonding and reduce gas migration risk, Super CBL™ EXP additive was included in the slurry design.

To help ensure effective displacement and manage equivalent circulating density (ECD), Halliburton modeled the cement and spacer properties using its iCem® cementing service hydraulic modeling software. Managed pressure cementing (MPC) techniques were also applied to minimize the potential for fluid influx during placement.

Result

The operation achieved full returns during displacement, confirming successful mitigation of lost circulation. Real-time monitoring validated lifting pressures and confirmed that the planned top of cement (TOC) objective was met.

Field observations showed that both spacer and cement were circulated off the top of the liner, indicating full cement coverage. Cement bond log (CBL) evaluations confirmed strong bonding throughout the zone of interest, including the 4 1/2-in. (114-mm) openhole liner and remedial scab, with no evidence of channeling or fluid influx.