Expandable Screen Research Articles

Subsea Development of Okwori and Nda Oil Fields, Niger Delta

Summary Addax Petroleum's operated Okwori oil field, offshore Nigeria, illustrated the benefits of reviving shelved projects, because of an insufficient return on investment using more traditional approaches, by applying more recent technical and contractual solutions. The Okwori project demonstrated the feasibility of developing small and geologically complex offshore oil fields in medium water depth of 440 ft with subsea technologies traditionally used for large fields. In the subsurface, the Okwori wells combined multiple selective completions hydraulically controlled from the surface with expandable sand screens as the downhole sand exclusion solution. This combination of equipment in subsea wells used to fully develop a small offshore oil field marked another technological first in Nigeria. Far away from pre-existing facilities and with less than 50 million bbl of median technical reserves at the time of project sanction, the Okwori oilfield development went a step further than the more usual subsea tieback to a pre-existing offshore production facility. The Okwori development plan was based on horizontal subsea trees flowing to a leased spread-moored floating production storage and offloading (FPSO) vessel by means of (6-in.) flexible subsea flowlines and risers. The Okwori leased production facilities had a built-in capability for additional tiebacks such as the Nda oil field, whose development was completed in October 2006, or for later redeployment in other parts of the acreage depending on further exploration and appraisal drilling. A review of the field operations to date highlighted a steep learning curve in the formulation of completion design, completion fluids, stimulation, downhole sand exclusion systems, and bean-up/bean-down procedures.

Cost-Effective Solutions for Corrosion-Resistant Expandable Screen Base Pipe in Sour/Brine Service

Abstract In today's competitive environment in the oilfield industry, the end-user must choose the very lowest-cost material that will meet the technical needs of the application. This requirement is passed on to the manufacturer, who must use materials that are appropriate yet still meet economic criteria. Another factor has been the expansion of field development into deeper, more corrosive environments, increasing the demand for corrosion-resistant alloys (CRAs) at a time when the demand and cost for stainless materials has increased. In expandable sand control systems, an added burden to the manufacturer is that this new technology must compete with existing non-expandable screens that are low-cost to manufacture with commodity type raw materials. One such example is 13Cr, being the first choice in a CRA for the base pipe in conventional sand screens. Although 13Cr is one of the least costly of the CRAs, it does provide the necessary corrosion resistance in mild H2S environments under a variety of chloride/temperature conditions. However, it lacks the ductility needed for 20 to 25% expansion as a solid expandable. 316L or UNS S31603 is a commodity CRA material with sufficient ductility and strength for use as an expandable screen base pipe, but its corrosion resistance is often questioned; particularly its resistance to chloride stress-corrosion cracking (SCC). This paper provides the data necessary to establish a performance envelope for S31603 and discusses the potential application of the material in several projects. Thus, S31603 is shown to provide a cost-effective CRA material for base pipes in sandcontrol screens. Introduction In expandable screen systems, the capability exists for the screen to be expanded against the borehole ID, virtually eliminating the annulus around the screen and 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(1). Finally, expandable screens can provide a larger production ID than is normally possible with traditional screens. The challenge with the expandable concept has been to provide not only materials that can maintain integrity in the more corrosive environments now being developed but also materials that provide the economic feasibility to allow them to be competitive in today's marketplace. The base pipe of a conventional, non-expanding sand screen is simply a pipe that has been perforated to allow fluid to flow in from the surrounding wellbore. The basic concept behind "solid expansion" of a screen system is simply to expand this perforated pipe downhole and thereby only slightly reduce the collapse strength as a result of having increased the diameter and reduced the wall. In contrast, a slotted pipe that has long thin slots cut lengthwise in the pipe has very little collapse strength after expansion. Therefore, while slotted pipe is easy to expand, it is also easy to collapse, and thus, is unable to prevent the wellbore from caving in.

Next-Generation Expandable-Completion Systems

This article, written by Technology Editor Dennis Denney, contains highlights of paper SPE 97281, "Next-Generation Expandable-Completion Systems," by Gareth Innes, SPE, Quentin Morgan, SPE, Ally Macarthur, SPE, and Annabel Green, SPE, Weatherford, prepared for the 2005 SPE/IADC Middle East Drilling Technology Conference and Exhibition, Dubai, UAE, 12–14 September. In many cases, openhole completions could provide maximum well productivity. However, use of the method has been impeded by the inability to achieve effective zonal isolation. An expandable completion that combines slotted- and solid-expandable technology and uses conventional unexpanded premium connections can deliver freely configurable completion architecture. Introduction Expandable sand screens provide direct contact of the screen with the formation as a means of reducing completion skin and improving sand-retention characteristics. The base technology is being integrated with new and conventional downhole technologies to enable multizone completions. A common conventional approach used to complete and commingle multizone unconsolidated reservoirs has been to, first, set and cement casing in the wellbore to isolate zones. The zones of interest then would be perforated before installation of a screen and placing gravel to control solids migration. This cased-hole sand-control technique has worked reasonably well but has a history of high completion skins. Also, the resulting smaller inside diameter makes the subsequent design and installation of selective-production upper-completion strings difficult, limiting the overall achievable functionality. In many cases, emulating an openhole high-deviation or horizontal completion strategy can increase well productivity. To enable these productivity gains and facilitate selective production handling, zonal-isolation technologies were combined with compliantly expanded screens to create a sandface completion with cased-hole functionality. Zonal-isolation technologies that satisfy functionality and expandable performance criteria include swelling elastomers and solid expandables. Expandable-Completion Development An expandable screen comprises three sandwiched layers: the base pipe, filter media, and outer protective shroud. The base pipe is slotted, as is the outer shroud. These slots open during expansion to accommodate the change in diameter, while overlapped layers of filter media slide across each other to maintain sand-retention integrity. The use of slots allows expansion ratios up to 80% greater than the original diameter. The entire length of the original design was expanded, including the connectors. The original expandable screen was designed for use in single-zone openhole applications. Large exposed filter area and variable borehole contact (known as compliant expansion) provide gravel-pack functionality. The design premise was that a compliantly expanded filter that could eliminate as much of the annular gap as practicable would promote rapid formation stabilization and minimize the movement of sand particles around the screen during the transient sand-production period. The large, directly exposed filter surface was designed to minimize pressure drops in the screen and sandpack composite caused by mud particles and formation fines.

Well-Completion Effects on the Performance of Horizontal and Multilateral Wells

This article, written by Technology Editor Dennis Denney, contains highlights of paper SPE 96530, "An Evaluation of Well-Completion Impacts on the Performance of Horizontal and Multilateral Wells," by L.-B. Ouyang, SPE, and B. Huang, SPE, Chevron Energy Technology Co., prepared for the 2005 SPE Annual Technical Conference and Exhibition, Dallas, 9–12 October. Well completion is critical in well design and the performance of the well for its entire life. The major objective for this study was to provide guidance in the design of completion configuration with a series of simulations with different completions in different flow and reservoir environments. Completion options including open hole, slotted liner, inflow-control devices, intelligent-well completions (i.e., downhole instrumentation and control system), perforated/cemented liner, wire-wrapped screen, external casing packers, gravel pack, and frac pack were reviewed. Introduction With many advanced well-completion options deployed in new wells, especially in deep- and ultradeepwater environments, well-completion details often are not taken into account in reservoir simulators. Reservoir simulators should be connected with wellbore hydraulics and tubing-performance prediction software regarding the ability to model complex well hydraulics, including an appreciation of the influence on deliverability of reservoir effects and completion design. This study evaluated the performance under different completion designs for two proposed gas wells and one existing oil well. Several potential factors that could affect well production were evaluated including pressure drawdown, wellbore damage, non-Darcy effect, zonal isolation, wellbore-pressure drop, fluid flow in the annulus, and well position. Simulation Tool A commercially available completion-modeling and well-planning simulation tool was used that models production fluids flowing from the reservoir through well completions into a wellbore. It is used for well-placement and -completion screening and/or design studies of local variations in reservoir properties. It allows scaleup and honors complex reservoir-description information from an Earth model to compute multiphase flow from the reservoir through the well completion, into the wellbore, and up to the wellhead. Through alternative well placement, the well behavior can be estimated for the given reservoir description and well-completion design. The steady-state oil-, water-, and gas-production rates as well as the production profile along the length of the horizontal wellbore can be calculated. Completion Option Different completion designs were proposed for the two gas wells, including openhole gravel pack (OHGP), cased-hole gravel pack (CHGP), standalone screen (SAS), cased-hole frac pack (CHFP), and expandable sand screen (ESS). For a CHGP or CHFP completion, an isolation string could be required. The detailed completion parameters for all the completion options are given in Table 1 in the full-length paper. Skin factor is a measure of the amount of additional pressure draw-down encountered because of mechanical or turbulent effects. The higher the skin factor, the larger the extra pressure drawdown, resulting in reduced well production. Mechanical skin is a factor closely related to well completion and independent of flow rate. The skin caused by turbulent effects (normally called non-Darcy effect, or non-Darcy skin) depends primarily on flow rate. Typically, non-Darcy skin is trivial and can be ignored for liquid wells or low-rate gas wells. However, the non-Darcy skin for high-rate gas wells could be as significant as the mechanical skin.

A light and flexible plasma tube array with a film substrate

— The plasma tube array is expected to lead to the realization of wall-sized displays. This method will realize an emissive-type display with a flexible screen and an expandable screen size. We have investigated a plastic film substrate with display electrodes for use as a flexible screen and successfully developed the world's largest bendable emissive display (1000 × 128 mm). The operating voltage distribution was improved compared to that with a plate substrate, and a sufficient voltage margin was maintained.

High‐luminance 1‐m‐long plasma tubes for wall displays

Abstract— The plasma‐tube array is expected to realize a wall‐sized display. This method will realize an emissive‐type display with a flexible screen shape and an expandable screen size. The shape of the plasma tube was investigated to realize high luminance, high luminance efficacy, and high flexural strength. As the result, a cylindroid tube is proposed to satisfy these demands. An experimental display of 1 m × 128 mm has been developed with these cylindroid tubes and it demonstrated a high luminous efficacy of 3.1 lm/W.

Openhole Expandable-Sand-Screen Completions in Brunei

Summary Expandable sand screens were deployed successfully as a sand-control device in two horizontal openhole completions in two geologically different offshore fields in Brunei. A critical success factor was the choice of a drill-in fluid (DIF) that maintained hole stability and gave a near-gauge hole while running and expanding the sand screen. Field experience and extensive research led to the choice of a synthetic-based DIF for one well but a water-based one for the other. Challenges unique to the deployment of expandable sand screens in these wells are discussed.

35.4: New Approach for Wall Display with Fine Plasma Tube Array Technology

AbstractA wall‐sized emissive full‐color display with fine plasma tubes using three electrodes is proposed. Each tube has an internal MgO overcoat and a phosphor layer. The experimental display was fabricated and the results will be presented. This method will realize a display with a flexible screen shape and an expandable screen size.