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Vol. 58 No. 2
February 2006
Dennis Denney, JPT Technology Editor
Downhole Wellhead Inspection
Drillpipe running tool used to carry the
CamScan EVO2 camera-inspection system.
EV Offshore Ltd. provides downhole, subsea, and well-intervention camera-inspection solutions. An operation was carried out in a development well in the Brechin field in the North Sea. While running the subsea completion, debris collected above the tubing hanger of the horizontal subsea tree, preventing the internal tree cap from seating correctly. A cleanout run with brushes was performed to remove the debris from the tree. To ensure that the area was clear of debris before continuing, the operator ran a downhole visual inspection of the inside of the tree. A special drillpipe running tool, with integral flush-through capability, was used to run the CamScan EVO2 on drillpipe. By use of this technology and use of downhole pressure, temperature, and other essential data, engineers were able to assess conditions visually in real time. The system uses a monochrome low-light camera and a high-definition color camera inside the running tool. The comprehensive pictures of conditions downhole enabled operations to be carried out accurately and with confidence. Pictures and short movies can be downloaded from the camera to a memory stick, from which they are transferred to a PC for use on the rig or for transmission onshore.
For additional information, e-mail david.clover@evoffshore.com.
Screen System for Sandface-Completion Problems
Baker Oil Tools’ Direct Pak screen system
clam-shell-type Cross-Coupling Connector.
The new Baker Oil Tools Direct Pak screen system was developed to solve two major sandface-completion concerns: hole instability in horizontal openhole gravel packs and annular bridging during long-interval cased-hole fracture treatments. Operators are opting to maximize reservoir contact and reserves recovery through long horizontal wellbores or long multilayered frac-pack completions. In this environment, sand-control screens and gravel-pack tools must handle large proppant volumes and high pump rates, effectively placing proppant or gravel-pack sand along the sandface completion in a void-free manner. The screen system comprises spirally wound crescent-shaped tubes welded to a shroud for maximum mechanical strength and minimum outside diameter. The simple clam-shell-type Cross-Coupling Connector is installed quickly. It allows for slurry flow between joints with hydraulic integrity without the need for timed connections. A key and keyway in the connectors make the system rotation-capable when used with a rotationally locked packer system. Large slurry-transition ports reduce flow velocity and minimize erosion. This screen system eliminates annular voids by use of multiple flow paths spread evenly across the entire surface area of the sandface completion. The screen system provides an additional flow path for slurry transport should annular bridging occur while packing. The spiral design helps centralize the screen and evenly distribute sand slurry to reduce the possibility of annular voids. The proppant slurry is transported directly to annulus voids that are the result of premature bridging or collapsed segments in the open hole. The screen system has been used in openhole gravel-pack completions in deepwater, high-rate gas wells in the Middle East in which the system encountered a highly reactive, unstable shale section in the producing interval. Complete packs were achieved in each application and were sand-free with greater-than-expected initial production rates.
For additional information, visit www.sandcontrol.com.
Evaluating Production Scenarios
IGL Oil and Gas Consultants has announced its MeasCap software, which enables operators to evaluate different oil and gas production scenarios and determine if existing equipment has sufficient capacity to process produced fluid. The software was developed to enhance the company’s capacity-modeling tool used to predict gas and liquid flow through process equipment. The software is a Microsoft Excel-based application that builds on the capacity models by managing the data flow throughout capacity studies and enables decisions on the basis of hardware changes necessary to optimize the flow of oil and gas through the process equipment. The software builds a library of process-capacity information that is available for future calculations, thereby providing a comprehensive analysis of process flow, operating conditions, and processing targets. The software was developed in response to a need to evaluate the most effective way to start up and maintain production from low-pressure wells in the Brae field to increase output and extend field life.
For additional information, visit www.iglconsultants.com.
Downhole Formation Measurements
Schlumberger’s MR Scanner is a wireline nuclear-magnetic-resonance logging tool. The tool uses a multiple-antenna design. The main antenna operates at multiple frequencies and is used primarily for fluid characterization. Its three frequencies of operation correspond to independent measurement volumes (shells) that form concentric arcs in front of the antenna. The eccentered mode of operation and sensor design provide four depths of investigation (DOIs), ranging from 1.5 to 4 in., that are maintained regardless of hole size, mud type, or temperature. Because the tool makes simultaneous measurements at multiple DOIs, it can provide a profile of saturation distribution and formation damage in a single pass. The high-resolution antennas operate at a single frequency, which corresponds to a slightly shallower DOI than that of the main antenna. These antennas provide rock-quality and producibility answers, even in thin beds. The tool is capable of logging going into the hole for comparison of main-antenna output with high-resolution-antennas output to identify light hydrocarbons. This logging mode enables acquisition of data in difficult environments. A flexible pulse-sequence programmer allows the parameters measured at the multiple frequencies to be acquired in a single pass, thereby eliminating the need for multiple logging passes. The sensors can be operated either separately or simultaneously at logging speeds up to 3,600 ft/hr.
The Schlumberger MR Scanner tool has a multifrequency main antenna designed
for fluid-characterization applications and two high-resolution antennas that
provide rock-quality and producibility answers.
For additional information, visit www.slb.com/understand.
Extend Stripper-Oilwell Production
Energy Production Systems’ Tubing
Rotator System being prepared for
installation at RMOTC.
Energy Production Systems has completed a year of technology testing of the company’s Tubing Rotator System at the Rocky Mountain Oilfield Testing Center (RMOTC) in Wyoming. The result was increased productivity and lengthened life of the tubing, by 400%, in a problem well. The testing validated the tool’s ability to extend the life and raise the production of stripper wells. Approximately 15% of U.S. oil production comes from more than 650,000 stripper oil wells (i.e., oil wells from which production has declined to less than 10 BOPD). This patented technology is a two-component system consisting of a rotating tubing hanger, which attaches at the wellhead, and a rotating tubing anchor installed downhole. It is intended to reduce the failure rate of wells by reducing the wear on tubing and pumping rods. In 2004, the system was installed in Well NPR-3, which had previously been considered for abandonment. The well had a long history of rod and tubing failures and had been shut in for 5 years because of poor economics. To test this technology accurately, a tubing string with 95 new joints was run in the well with the system. The well was run on a continuous pumping cycle for 1 year. There were no failures in the well from the time of installation to September 2005, when the completion was pulled from the well. Production levels increased to levels 3 years before shut-in. Tubing-wear inspection showed improvement over pretest failure rates (failure every 4 months), extending the life of the tubing.
For additional information, visit www.tubingrotator.com.
