Patrick York

Expandable Tubular Solutions

Two challenges facing operators as the energy industry moves into the next century are accessing of new reservoirs that currently cannot be reached economically and maintaining profitable production from older fields. Recent advances in one of the oldest and most fundamental areas of exploration and production, namely tubular technology, will play a key role in meeting these challenges. A method has been developed whereby the diameter of solid tubulars can be expanded downhole. This paper will describe the process and how this significant technological breakthrough provides cost-effective solutions to several tubular problems that have loomed as obstacles to comprehensive reservoir exploitation. In deepwater and subsalt environments such as the Gulf of Mexico, the ability to expand casing and tubing in-situ enables hole-size maintenance and conservation of internal tubular diameter for increased efficiency. Hence, operators are less likely to run out of hole diameter before evaluating all pay zones. Operators can now use smaller holes to drill deeper vertical wells or to extend the reach of deviated wells to access untapped reservoirs. In older fields, existing wellbores can be retrofitted with expanded tubulars for repair purposes or to increase strength and integrity. In the latter case, deeper high-pressure objectives can be supported, and thus, new in-fill wells can possibly be reduced in number or even eliminated. In addition to a description of the process employed to expand solid tubulars, the paper will present applications of expandable tubular technology and results of large-scale testing that has been conducted in support of the applications. Potential commercial applications are also presented.

Expandable Tubulars: Field Examples of Application in Well Construction and Remediation

As the oil and gas industry has matured, three broad-reaching and long-standing issues that affect virtually every well have assumed heightened importance: conservation of hole size, hydraulic isolation of selected zones, and maximization of well life. All of these issues involve one of the industrys most fundamental technologies, wellbore tubulars. Until recently, resolving these issues with conventional tubular technology was becoming ever more difficult, especially in deep-drilling and extended-reach applications, in wells utilizing liner hangers, and in aging wells containing deteriorating casing. A revolutionary new technology-expandable tubulars-has recently been introduced and has successfully addressed these issues in commercial applications. The basic concept underlying expandable-tubular technology is simple: a mechanical expansion device, known as an expansion cone or mandrel, is propagated through downhole tubulars utilizing hydraulic pressure. The progress of the cone expands the tubulars to the desired internal and external diameters in a plastic deformation process known as cold drawing. In drilling applications, a specially-designed liner hanger utilizing the new expandable-tubular technology conserves hole size by eliminating the need for a conventional liner hanger/liner hanger packer, and provides a superior pressure seal compared to the old technology. In cased wells, expandable casing is cladded to existing casing, either to repair or strengthen the existing casing, with minimal decrease in wellbore inside diameter (ID) and flow potential. Expandable tubular solutions have been successfully installed in the Gulf of Mexico, in U.S. inland wells, as well as in large-scale field trials. This paper briefly describes the technical concepts upon which expandable tubulars are based and gives an overview of expandable-tubular applications. The paper then focuses on the most recent field installations, including systems installed during the first quarter of 2000. Discussions of field examples will contain customer objectives, job design, installation procedures, ultimate results and best practices learned.

Solid Expandable Tubular Technology - A Year of Case Histories in the Drilling Environment

Maximizing hole conservation while optimizing well economics in both conventional and deepwater wells is a continual challenge. Addressing these challenges with new technology has provided some significant solutions, but the uncertainty when utilizing new technology with no proven track record must be risk-weighted. Solid Expandable Tubulars (SETs) have been installed in both openhole and cased-hole wellbores from November of 1999, in a variety of environments in wells on land, offshore and in deepwater to solve a range of drilling and completion challenges. This paper will discuss the drilling case histories in depth including : * Descriptions of drilling challenges surrounding the use of SETs and their next best alternatives ; * Risk analysis leading to the use of SETs ; * Discussion of the advantages and disadvantages of using SETs ; * Operational lessons learned during installations of SETs.

Realization of the MonoDiameter Well: Evolution of a Game-Changing Technology

Solid expandable tubulars are used to slim deepwater wellbores. The expandable openhole liner system expands and seals the outside diameter of an expandable casing against the inside diameter (ID) of a string of conventionally set casing. Additional wellbore slimming was realized with the ability to expand and seal sequentially installed expandable casing strings or nested expandable liners. This procedure reduces typical hole size by approximately 50%. Use of nested expandable systems facilitates the use of smaller, more economical drilling vessels to drill deepwater wells.

Eliminating Non-Productive Time Associated with Drilling Trouble Zones

Cost overruns can easily manifest during well construction due to unexpected issues including lost returns, differential sticking, and narrow pore pressure/fracture gradients. To better plan for potential overruns, operators sometimes earmark 10 to 25% of the Authorization for Expenditures (AFE) to cover the unexpected, which can significantly impact drilling budgets. Technical and operational risks versus the potential return on investment (ROI) are critical factors in determining whether a project proceeds. Too often the best drilling practices used to address trouble zones are limited to a few conventional methods with a narrow range of effectiveness. Also, a lack of rock mechanics knowledge can prevent the most efficient solution being applied. Some operators are implementing planning programs that assess and integrate the latest processes and technologies to address drilling risks up-front. Cutting-edge technologies such as managed pressure drilling methods, drilling with casing / drilling with liners, and solid expandable casing have been highly effective. Implementing proactive evaluation processes and applying the latest tools and techniques can efficiently address operational risks and trouble zones to ultimately reduce NPT and associated costs. Employing common practices and technologies that are typically ineffective and that drive up NPT cost should be considered unacceptable. Common sense well construction evaluation processes used in conjunction with validated conventional and new technologies have proven their worth by reducing expenditures and risks, preventing the loss of wells, and increasing the operator’s ROI. This paper will review real drilling challenges that have been encountered and the common practices that were employed to address these drilling hazards. This paper will compare and contrast how these same circumstances have and can be addressed much more efficiently with engineering evaluation processes that help determine the best drilling tool and/or technique to mitigate risks and reduce NPT.