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Use of Cement Kiln Dust (CKD) in Low Temperature Cementing to Reduce Transition Times

IP.com Disclosure Number: IPCOM000231090D
Publication Date: 2013-Sep-25
Document File: 7 page(s) / 223K

Publishing Venue

The IP.com Prior Art Database

Abstract

The present invention provides cementing compositions comprising cement kiln dust (CKD) for use in low temperature (e.g., about 60°F or less) well cementing applications to reduce transition time. In an embodiment of the invention, CKD is incorporated into a standard deepwater cement system to lower the transition time thereof at lower temperatures.

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Use of Cement Kiln Dust (CKD) in Low Temperature Cementing to Reduce Transition Times

Abstract

     The present invention provides cementing compositions comprising cement kiln dust (CKD) for use in low temperature (e.g., about 60°F or less) well cementing applications to reduce transition time. In an embodiment of the invention, CKD is incorporated into a standard deepwater cement system to lower the transition time thereof at lower temperatures.

Description of the Invention

     Hydraulic cement compositions are commonly utilized in the construction and repair of oil and gas wells. For example, hydraulic cement compositions are used in primary cementing operations whereby strings of pipe such as casing or liners are cemented in well bores. In performing primary cementing, a hydraulic cement composition is pumped into the annular space between the walls of a well bore and the exterior surfaces of a pipe string disposed therein. The cement composition is permitted to set in the annular space thereby forming an annular sheath of hardened substantially impermeable cement therein. The cement sheath physically supports and positions the pipe string in the well bore and bonds the exterior surfaces of the pipe string to the walls of the well bore whereby the undesirable migration of fluids between zones or formations penetrated by the well bore is prevented. Hydraulic cement compositions are also commonly used to plug lost circulation and other undesirable fluid inflow and outflow zones in wells, to plug cracks and holes in pipe strings cemented therein and to accomplish other required remedial well operations.

     In carrying out primary cementing as well as remedial cementing operations in well bores, the cement slurries utilized are often lightweight to help prevent excessive hydrostatic pressure from being exerted on subterranean formations penetrated by the well bore. As a result, a variety of lightweight cement slurries have heretofore been developed and used including foamed cement slurries. In addition to being lightweight, a foamed cement slurry contains compressed gas that improves the ability of the slurry to maintain pressure and prevent the flow of formation fluids into and through the slurry during the time in which the cement slurry changes from a fluid to a hard set mass. Foamed cement slurries are also advantageous because they have low fluid loss properties.

     Well completions in water over 1000 feet deep often require special techniques to install conductor casing. Well completions at depths in excess of 2,000 feet of water are often referred to as "deepwater" operations. In deepwater operations, the formations where conductor pipe is cemented that is less than 2,000 feet below mud line (BML) are generally young geologically and are not well consolidated. The formations generally are the product of erosion from the continental shelf. This can cause either of two problems in cementing. The formation may be so weak that it may fractu...