A multitude of challenges exist when cementing production liners for deepwater operations. In many platform operations, cutting windows to sidetrack and drill highly deviated well paths to intersect reservoir targets result in difficulty obtaining adequate casing standoff due to tight inside diameter (ID) restrictions from previous casing architecture. Many of the zones near the target interval may have significant pressure depletion which can lead to expensive Synthetic Based Mud (SBM) losses and associated non-productive time (NPT). The size of the production liner is dependent on the wellbore architecture and completion plan. Thus in most cases, the borehole must be under-reamed in order to provide for adequate cement sheath thickness. In these cases, centralizer selection and placement can be challenging or all together impractical. Cementing in SBM environments has also been traditionally more challenging because special considerations for spacer/surfactant/mud design and testing are required to effectively displace the mud and "water-wet" the formation/casing for good quality cement-bonding. Technology improvements in spacer and surfactant package formulations provide a more qualitative method for optimum surfactant design to maximize mud removal and provide a bonding surface to the formation. Liner hanger selection may not always provide the capability for pipe rotation which has shown to be very effective for mud removal and increased circumferential cement coverage. Without pipe rotation, additional key techniques for successful cementation must be prioritized. A process driven decision matrix is presented along with a recent selection of successful production liners to support the design concept.

Performing cementations in a deepwater environment poses many unique challenges during the drilling and completion operational phases in the Gulf of Mexico. These challenges add further difficulty and risk to an already complex operation. During the course of constructing the wellbore, it may be necessary to perform un-scheduled remedial cementing operations to acheive the main objectives. Squeeze cementing performed to remediate undesireable well conditions which may have resulted during the drilling phase (major mud losses) or as a result of a poor primary cement job (insufficient zonal isolation) must be thoroughly analyzed during planning to understand all the critical parameters needed to execute the right plan. When designing for a squeeze job, key decision factors during the planning process must be addressed for a successful outcome. The success or failure of a squeeze cement operation relies on 1) understanding what is the objective of the squeeze operation 2) determination of the optimum cement placement depth, 3) development of an effective placement procedure with proper technique and down-hole tools employed, 4) proper design of cementing fluids including washes and spacers, 5) flawless execution with a detailed pressure/rate/volume record of fluid injection, and 6) a meaningful post evaluation of the squeeze operation’s results to determine if objective was met. This paper will provide guidance on addressing the key decision factors, development of a proper placement strategy, general design guidelines for appropriate cementing fluids to employ, and how to evaluate if the objective was met. Results will be presented from recent deepwater case histories to demonstrate the successful application of this methodology for squeeze jobs and the techniques used.