Halliburton saved operator $1.2 million and 16 days of rig time

Overview 

Impedance values of fluids and lightweight cements are so close that conventional logging and analysis techniques often confuse them. This can cause companies to try to squeeze cement into perceived “voids,” which may not actually exist – wasting time and money. A large US operator in southern Louisiana used light cement in three wells. The operator had to be sure that cement coverage extended throughout the entire Travis Peak formation, which lies below freshwater aquifers. Halliburton Advanced Cement Evaluation (ACESM) service reliably distinguished between fluids and the lightweight cement in the annular space. Analysis clearly showed two of the three wells had adequate coverage. It also showed that the third needed a cement squeeze to ensure complete coverage of the Travis Peak formation. Based on squeeze costs for the third well, the operator estimates it avoided spending $1.2 million and 16 days of rig time on the first two wells

Challenge

Traditional cement evaluation services have difficulty properly characterizing lightweight or foamed cements. Because these cements have impedance values close to those of annular fluids, such as mud or water, conventional interpretation can lead analysts to believe that the cement bond is inadequate, causing them to order expensive – and completely unnecessary – remedial cementing. 

Solution 

Halliburton ACE service can analyze any standard cement bond log data acquired with any acoustic tool used for cement evaluation – even data generated from competitors’ sonic and ultrasonic tools. Halliburton can run ACE service with data acquired from CBLs, RCBLs, ultrasonic scanners, openhole sonic, or LWD sonic tools.

To provide conclusive evidence of proper cement coverage and integrity through the Travis Peak formation, Halliburton recommended the post-processing of both CBL and CAST-F ultrasonic data using ACE service.

Result 

Information provided by Halliburton ACE service satisfied regulators. Clearly, the first two wells did not need any additional work to cover the Travis Peak formation and protect the environment. Based on the costs of remediation for the third well, the operator estimates it saved a total of $1.2 million and 16 days of rig time on the first two wells. Without ACE service, regulators might have forced the company to spend this time and money to perform unnecessary cement squeezes because of ambiguous cement evaluation results.

The operator also credits Halliburton ACE service with helping it prevent future environmental problems and potential liabilities. Ambiguous data might have led some companies to argue that a cement squeeze was not necessary when, in fact, it might have been. Problems could then develop that might disrupt future production and cost the company even more money for remediation.