A new technology recently introduced to the oilfieldexpandable-sand-screens -has focused on providing solutions for the inherent weaknesses in traditional sandcontrol completion techniques that can affect borehole stabilization, production rate, and completion costs. Gravelpack operations can also increase logistical requirements, and in many wellbore scenarios, can be difficult to perform. Finally, stand-alone screen completions are subject to borehole collapse. This problem can lead to sand production and screen-erosion during production. This paper will review a new expandable sand screen system that has the capability to provide a solution for some of the inherent problems discussed above. The discussion will focus on 1) the development of the technology required to expand perforated pipe plastically, 2) the tools and techniques employed, 3) the development of the screen, 4) the testing results, and 5) the first field trial of system.The innovative sand screen system provides the capability for the screen to be expanded against the borehole ID. The annulus around the screen is then virtually eliminated, which in turn, eliminates the need for gravel packing. Also, this increases the sand screen surface area, thus reducing pressure drop across the filter and increasing production rates. Because of its high strength, the expanded screen can provide superior support to stabilize the borehole, which then minimizes the potential for sand production. Finally, the new screen provides a larger production ID than is normally possible with traditional screens.

Many traditional sand-control completion techniques have inherent weaknesses that can significantly affect borehole stabilization and completion costs. Also, gravel-pack operations can increase logistical requirements in horizontal and extended reach wellbores. Finally, stand-alone screen completions are subject to borehole collapse and screen-erosion during production. A new technology recently introduced to the oilfield - expandable-sand-screens - has focused on providing solutions for these problems. This paper will review a new expandable sand screen and associated expansion tool that shows promise of solving some of the inherent problems discussed above. The innovative sand screen system allows the screen to be expanded toward the borehole ID. This principally increases the sand screen surface area, thus reducing pressure drop across the filter and increasing production rates. Secondly, expansion helps to stabilize the borehole to minimize the potential for sand production. The new screen eliminates the need for gravel packing operations in many wells and provides a larger production ID than is normally possible with traditional screens. The discussion will reviewthe development of the technology required to expand perforated pipe plastically,the tools and techniques employed,the development of the screen, andthe testing results. The discussion will also include a review of the first field trial of the expandable sand screen system. Introduction To prevent sand production in horizontal wells, screens are typically inserted into the openhole-producing zone.1,2,3,4 After the well has been on production for a period of time, the formation can become somewhat unstable resulting in excess sand production and hole-sloughing. Hole-sloughing can lead to plugging and subsequent erosion of the screens. In some cases, significant external loads can be applied to the screen as a result of wellbore collapse. These external loads can collapse the screen if it does not have sufficient structural integrity. To provide the best level of sand control and wellbore support, the annular space between the screens and wellbore can be gravel packed. However, to create a reliable horizontal gravel pack completion with a high probability of success is difficult in some well conditions.5,6,7,8,9,10 Also, the installation of a sand-control screen reduces the production ID that is otherwise available, and designing for gravel pack placement around the screen may reduce the ID still further. The solution chosen to address this problem was an expandable filtration system with enhanced collapse-strength integrity. The completed product should be an expandable sand screen that can be expanded inside a 6–1/8-in. open hole and provide sand control during production. The system will include a screen, running tool, screen hanger, and screen-expansion tool. (Fig 1) The successful development of this system would result in the following measurable results:Reduced failure rate due to elimination of hot spots (erosion) over timeIncreased hole size for re-entry and work-over capabilitiesIncreased production ratesPossible reduction in bore size for drilling-cost reductionImproved reliability due to greater installation successInstalled cost comparable to horizontal gravel packed wells. Because of the complexity of the solution and the commitment required, the decision was made to use the "Product Development and Commercialization" (PD&C) method for this project. The PD&C method involves the creation of a development team made up of Technology personnel that are entirely dedicated to the development of the product. In addition, representatives are included from manufacturing, procurement, sales, and operations on the team.

A pneumatically governed, wireline-retrievable subsurface safety valve directly operated by local tubing pressure change at the valve has been developed for natural gas storage wells. This paper provides a detailed operating theory and description of the valve, which utilizes a control chamber volume of well-effluent to maintain a history of well bore pressure. The "memorized" pressure is constantly compared to current flowing tubing pressure via a sensing piston. When an established differential pressure value is exceeded, the sensing piston allows valve closure and control of the well. A "flapper-type" closure valve with an automatic reset mechanism allows the tool to be placed back in service with manipulation of tubing pressure. Application of this technology is best suited to gas storage wells with a routine flow rate change caused by seasonal variation in gas demand. In these wells a fixed-rate flow sensing valve is not preferred. The viability of this technology has been demonstrated by prototype testing in a producing gas storage well. This new concept will be of particular interest to gas storage well operators seeking simple, subsurface-controlled well protection.

In 1985 and 1986 at least one joint industry project studied the concept of using a flexible riser to service a subsea well. As one step to help prove the concept viable, wireline tools were successfully installed downhole in a test well through a section of flexible pipe. Thesimulated riser, (flexible pipe) was offset 26? from the wellbore center, while maintaining aradius curvature of 30? into the well tubing. The results of this test could help establish a call out wireline service using afloating service vessel (Figure 1). The results also demonstrated the system would be applicable to floating production systems using flexible risers. INTRODUCTION Wireline tools used for production well maintenance are rigid over their length, and, except fOr extreme "dog legs", not required to negotiate short bends when installing thesetools in a wellbore. Installing conventional wireline tools through a flexible pipe requires consideration of several factors, i.e., tool length, tool OD, tubing size, riser size and curvature of the riser, as well as the dynamics involved. A test well installation was made selecting a tubing size of 3 1/2" 00 coupled to a 4" IO flexible pipe to simulate the riser. By using knuckle joints in the wireline service string and maintaining a 30? radius in the flexible pipe, quite a few conventional wireline tools were successfully installed, retrieved and/or operated in the test well. These same wireline tools were again installed in the test well using a conventional lubricator mounted directly on the well. Datawas collected and compared with the flexible pipe run data. Results indicated that wirelineoperations can be conducted through a flexible pipe. A separate test conducted at the same time, measured possible wiretracking effects inside the flexible pipe. TEST OBJECTIVES The following objectives were established for the test:Can wireline operations be successfully performed through a flexible pipe used as a riser? If so, identify the components of a wireline tool string.Can jarring operations be conducted at an acceptable level to set and retrieve wireline tools?Identify 3" nominal wireline tools (chokes) that pass through a 4" ID flexible pipe while maintaining a 30? minimum radius.Identify production logging tool packages for passage through this same flexible pipe.Verify tool passage/riser ID/radius calculations for wireline (slick) and production logging tools.Use of tool passage/curvature calculations for sizing tool packages.Assessment of wireline tracking inside the flexible pipe that resulted from the tests. TEST ARRANGEMENT The Test Well [total depth - 6500?) was completed with 3-1/2" OD (3" nominal) EU tubing with the equipment installed in the tubing string as shown in Figure 2. In order to simulate a flexible riser above the wellhead, a crane was used to support the wireline lubricator and flexible pipe, as illustrated in Figures 3 and 4. A fixture referred to as a "spine" was fabricated from 3-1/2" pipe. This spine was mechanically bent to form a 30? radius.

Subsurface safety valves for large-completion, gas-cavern storage systems must comply with the economic, safety, and regulatory restraints required by industry standards in addition to satisfying the demanding environmental restraints imposed by gas wells with significantly high flow potentials. In addition, location of the valve and all protected systems must also be given careful consideration in completion design since this type of well is prohibitively expensive to kill if workover is required. A direct-control subsurface safety valve has now been developed to meet these stringent requirements. The valve, which can be installed in the tailpipe below the packer, can be expended into the cavern, if necessary, and has the capability to provide efficient operation with minimal pressure loss at anticipated high flow rates. This paper will discuss the history and field testing of the earlier prototypes of this valve and how the unique design criteria of the new design address the problems of valve mechanism damage that are generally attributed to high-flow-rate closures. An actual case history from a storage facility in Germany will demonstrate the advantages that the newly designed valve can provide. At present, two valves have been installed, with one being used to conduct long-term evaluations. All closures have been as predicted with no subsequent leakage or damage to the valve or lock. The new valve design has demonstrated excellent reliability in a demanding, high-flow-rate environment and maintains structural integrity during high-energy valve closures. Elimination of a hydraulic control system also allows unrestricted setting depths. Design analyses, surface testing, field testing, and wireline applications all indicate that a poppet-closure mechanism can be combined with "up-to-set" and "down-to-set" lock mandrels to successfully to address the problems previously associated with high-flow-rate closures in applications of this type. BACKGROUND INFORMATION The underground storage facility in Germany was created by leaching out salt to create large storage caverns. As a result of the leaching process, the wells had to be drilled with large casing. Typically, 13-3/8 inch (.34 m) casing is used with the completion, which consists of a 13-3/8-inch (.34 m) permanent packer and 8-5/8-inch (.22 m) production tubing and tailpipe. P. 139^