Cemented completion provides an excellent opportunity for low cost drilling techniques and simple well designs to reduce well delivery costs without impact on safety or well integrity. In this concept, the completion is run straight into the open hole and cemented in place. There is no need to run a liner and perform a traditional cleanup. The cement effectively replaces the production packer. Achieving a good cement job is essential to a successful operation. A failed cement job would require cutting and pulling of the completion before running a conventional completion and packer, unless there was a high confidence in the outcome of a remedial cement job. Therefore good conditions for cementing are a definite requirement. Gas production and gas storage wells are particularly demanding on the cement sheaths. A failure of the sheath through de-bonding, cracking or plastic deformation results in formation fluids to enter the annulus, which pressurises the well and makes it unsafe to operate, the consequences are either losing the well altogether or, at best, an expensive intervention. Advanced cement technology combined with state of the art software are used today to ensure a complete long-term zonal isolation of the cemented completion. The software can model the stresses in a particular well over its entire life, including changes to the formation properties, well completion parameters, formation in-situ stresses, and operating envelope and can compare the properties of different available cements to enable the optimum cement to be selected (hole size, cement sheath thickness).The following paper will describe the process and the engineered cement used to ensure integrity of the cemented completion and lists case histories of the 3 cemented Completions successfully cemented Onshore Netherlands.
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