A recurring issue in the petroleum industry is the performance of cement in relation to its primary role of providing zonal isolation. Enhanced understanding of this subject offers the possibility to improve the planning and design of the cementing job to minimizing the risk of poor bonding of cement and loss of well integrity. The design and execution of the cement job is by no means an easy task, mainly due to the complexity of the material and process, and the variety in conditions one can encounter downhole. Thus, screening of different materials and conditions is necessary to optimize the success of a cement operation.
This work focused on experimentally testing cement plugs to be able to understand the sealing ability of cement to a casing at relevant temperatures and pressures. A built-for-purpose test setup was designed and assembled, and the goal of this work was to test this new setup and to establish a proper baseline for future test on various cement systems.
The setup consists of a test cell containing the cement plug, an automated pressure regulator used for generating a pressure differential across the cement plug and flow meters to measure the flow rate through the cement plug. The output data from the tests is the differential pressure needed to have breakthrough of gas, and the connection between the flow rate and differential pressure across the cement plug. The possible manipulated variables for the test setup is the cement type and casing surface properties.