The cement slurries normally employed during the cement job are lightweight, extended lead cement systems with a tail cement of higher density placed in the lower section of the cemented interval. In common practice, both lead and tail cement systems are designed without any gas control capabilities. Further, certain lightweight cement systems are prone to gel quickly, thereby accelerating the loss of hydrostatic pressure exerted on the column of tail cement below. Conventional cement designs typically employed in the shallow section of the wellbore normally possess no ability to mitigate flow.

In the Gulf of Mexico the root cause of annual flow after cementing is due to loss of hydrostatic pressure of the cement column. This project is to perform a cement pulsation technique on three-offshore shallow-water wells, whereby the leassee/owner of the wells will cooperate in donation of wells for the pulsation cementing process and collection of data to prove viability of the technology for novel use in the offshore environment. Cement pulsation is a simple and inexpensive technique that effectively maintains the hydrostatic pressure on the cement column. Low pressure pulses applied during the cement curing process retains the hydrostatic pressure of the cement column until the cement has developed sufficient strength to resist any influx from the formation.

Loss of well control is a serious operational safety hazard. This project and the resulting deliverables will enable assessment of the cement pulsation technology to mitigate annular flow after cementing, and provide solid, fact-based information to determine this technology as a "best available and safest technology."

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Last Updated: 07/28/2008, 01:36 PM