The advent of deepwater drilling and the increasing number of deepwater discoveries have led the energy industry to develop new completion design philosophies and technologies for challenges that did not exist in the oilfield less than a decade ago. As a result, the numerous deepwater developments and the experience gained have led to new levels of efficiency and reliability in completion design; risk and economics analysis have joined the technology, safety, and environmental aspects in educated decision processes. Two challenges in particular have created opportunities for advancement. First, rig-time costs for operating in deepwater are so high that efficiency and reliability had to be emphasized to minimize nonproductive time during completion installation. The result was the development of special tools and techniques that allow operators to reduce the number of trips in the hole and to accelerate online time on the drill floor. The effort to decrease nonproductive time paralleled a second important objective: increasing the time of field reliability. Because many deepwater wells are subsea, intervention operations and costs are prohibitive; thus, completions must be designed to minimize or eliminate the need for interventions during the life of the well. This objective intensified the need for better equipment designs with respect to longevity, corrosion, and erosion-resistant materials, work rating specifications, and remote monitoring and control equipment. Although some deepwater projects are completed with dry trees from platforms, this article focuses on subsea wells and the major drivers that have differentiated their completion design processes from those of conventional designs. It also compares some of the solutions adopted to address risks and economic issues and discusses how these solutions vary according to corporate design philosophies and local best practices. Examples of design solutions are discussed for various deepwater areas, including the Gulf of Mexico, West Africa, and Southeast Asia. Introduction Most industries in the world today utilize project management processes and tools to help ensure that final goals are achieved on time and within budget. The oil and gas industry does an excellent job of managing topsides construction projects of new fields using project management tools, but still today the well construction part of projects does not generally utilize these tools to their full potential. The projects are often handed over to "operations" to do the well construction phase, where normal operating procedures are used. Our Completions team has found that to deliver major completions projects, wherever in the world, we must manage our business using strong project management principles rather than the "business as usual" operations-style philosophies. By doing this, we can more effectively deliver the right products and services to the field, on time and within the original budget set out. We can assign the right level of resources at the right time and work around issues that always crop up with mature risk management and contingency plans. The following are the key project management principles we use today:Work breakdown structure (WBS)Milestone planning (GANNT charts)Task assignment (RACI charts)Risk management (Quantitative/Probabilistic)Management of change (MOC)Integration management

Many of the water injectors in sand control environments are being completed as long open holes due to higher injectivities attainable with such completions. Although target rates may often be achieved without any cleanup chemicals in production wells, injection wells require filtercake cleanup, in cases where • producing the well prior to injection is not feasible or desirable, (e.g., limited storage capacity on the rig, or artificial lift requirements due to low pressure or injection into water leg) • injecting above frac pressure is either not feasible (e.g., very high frac pressures and pump limitations) or not acceptable (e.g., sweep efficiency, premature water breakthrough, uncontrolled fracture height growth).Although a large variety of filtercake cleanup techniques and chemistries are available in the industry, most of these solutions are effective in producers. As demonstrated through laboratory experiments, achieving consistently high injectivities requires removal of drill solids from the filtercake, through either dissolution (e.g., acid formulations utilizing HF) or effective displacement techniques that will not result in injection of these solids into the formation pore throats (SPE 77449). In addition, an effective filtercake removal (including drill solids) in long open holes without inducing high losses into the formation (so that the wash pipe can be pulled out and a mechanical fluid loss control valve can be activated) remained as a formidable challenge, which becomes even a bigger challenge in wells drilled with conventional oil based muds (OBM), particularly in reactive shale environments.In this paper, we present a novel technique that addresses these challenges, proven through field application on a standalone screen water injector in Nigeria. The technique involves displacement of OBM from openhole with a viscous spacer pill containing a demulsifier, followed by completion brine containing a mutual solvent to weaken the filtercake without attacking the bridging agents, subsequently performing a high rate viscous pill displacement to remove the external cake, and finally spotting a water-based self-destructive fluid loss control pill to control the losses while pulling the wash pipe. Laboratory testing for designing the displacement stages, field execution, and well performance evaluation are detailed.

Success in deploying sand control systems is critical to guarantee the integrity of wells during their productive life. This is even more crucial when dealing with ultra-deepwater high-rate gas wells. This paper will describe the challenges and the lessons learned from the successful 2021 completion campaign of X field in East Africa in which six gas producer wells were completed with openhole gravel pack using shunt tubes technology in water depths ranging from 1840 m to 2149 m. The overall completion design philosophy was to rely on field-proven technologies and industry-accepted "best practices" to maximize safety and reliability. This objective was pursued in all phases of the project for timely completion of the wells while minimizing the chance of failure. Extensive testing on formation rock cores and completion fluids was performed before the start of drilling to identify the best sand control strategy and to avoid all potential issues such as formation damage or fluid incompatibility. State-of-the-art completion equipment was selected considering all potential contingencies associated with operations in an ultra-deepwater environment in a remote location. This document will describe the activities carried on during the different phases of the project: design, preparation, execution, and post-job interpretation. The goal of preventing solid production without impairing the well productivity was achieved successfully. This was confirmed from well testing interpretation where neglectable skin was detected. At the same time, it was possible to carry on the completion activities on time and on cost despite the remote location and the challenges related to the ultra-deepwater environment.