skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Downhole Vibration Monitoring & Control System

Authors:
Publication Date:
Research Org.:
Aps Technology
Sponsoring Org.:
USDOE
OSTI Identifier:
897545
DOE Contract Number:
FC26-02NT41664
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English

Citation Formats

Martin E. Cobern. Downhole Vibration Monitoring & Control System. United States: N. p., 2006. Web. doi:10.2172/897545.
Martin E. Cobern. Downhole Vibration Monitoring & Control System. United States. doi:10.2172/897545.
Martin E. Cobern. Sun . "Downhole Vibration Monitoring & Control System". United States. doi:10.2172/897545. https://www.osti.gov/servlets/purl/897545.
@article{osti_897545,
title = {Downhole Vibration Monitoring & Control System},
author = {Martin E. Cobern},
abstractNote = {},
doi = {10.2172/897545},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Dec 31 00:00:00 EST 2006},
month = {Sun Dec 31 00:00:00 EST 2006}
}

Technical Report:

Save / Share:
  • The project continues to advance approximately per the revised (14-month) schedule. Tasks 1-3 (Modeling, Specification and Design) are all essentially complete. Work has begun on designing the test equipment for the Test and Evaluation (Tasks 4 & 5.) One of the intents of this project is to not only dampen vibration above the damper, but to also dampen vibrations below the damper. This is accomplished by smoothing out the discontinuities as the bit drills ahead. The model has the capability to simulate the drilling looking at the depth of cut along the discontinuities. It can also look at the amountmore » of time that the bit is in contact with the formation. It is found that under some conditions the vibrations increased the discontinuities due to resonant conditions. In the ideal situation, the damper reduces the discontinuities and smooths out the drilling. APS looked at a wide range of spring stiffness and damping properties to determine the optimum damper. Spring rates of 10,000 lb/in to 60,000 lbs/in were analyzed. The best compromise is at 30,000 lb/in for the 6 3/4 inch tool. Low spring rates would require large displacements for the damper, while stiff springs do not provide enough motion for the damper. Several damping concepts were analyzed: (1) The first thought was to have a damper providing high damping in the upward direction and low damping in the downward direction. It was found that this increased the vibration by wallowing out the troughs of the discontinuities leading to increased displacements at the bit. (2) Another method investigated was having increased damping at high acceleration levels and less damping at lower acceleration levels. This gave improved results. (3) Constant damping so far provides the damping situation. With the proper damping level the damper can smooth out the discontinuities and provide smooth drilling. However, the damping values are different for different drilling conditions. Different WOB and ROP require different damping coefficients and therefore must be constantly adjusted to provide optimum drilling conditions. The DVMCS system is designed to provide this adjustment (4) Other methods are still being investigated. One method is a constant force damper that might provide optimum damping over a wider range.« less
  • The purpose of this program is to develop the Drilling Vibration Monitoring & Control System (DVMCS) to both record and reduce drilling vibrations in a ''smart'' drill string. It is composed of two main elements. The first is a multi-axis active vibration damper to minimize harmful axial, lateral and torsional vibrations, and thereby increase both rate of penetration (ROP) and bit life, as well that the life of other drillstring components. The hydraulic impedance (hardness) of this damper will be continuously adjusted using unique technology that is robust, fast-acting and reliable. The second component is a real-time system to monitormore » 3-axis drillstring vibration, and related parameters including weight- and torque-on-bit (TOB) and temperature. This monitor will determine the current vibration environment and adjust the damper accordingly. In some configurations, it may also send diagnostic information to the surface via real-time telemetry. Phase I of this program addresses an evaluation of the environment in which the DVMCS will operate; modeling of a drillstring response including the active damper; a top-level design of the mechanical and electronic systems; analyzing the anticipated performance of the damper by modeling and laboratory testing of small prototypes; and doing preliminary economic, market, environmental and financing analyses. This phase is scheduled to last fourteen months, until November 30, 2003. During this first quarter, significant progress was achieved on the first two objectives, and work was begun on several others. Initial designs of the DVMCS are underway.« less
  • The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program entails modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype. The project continues to advance, but is behind the revised (14-month) schedule. Tasks 1-3 (Modeling, Specification and Design) are all essentially complete. The test bench for the Test and Evaluation (Tasks 4 & 5) and the laboratory prototype were constructed by the endmore » of the period. During assembly, however, several of the key subassemblies became galled together, and had to be cut apart. These parts are being remachined with harder surfaces to prevent recurrence of this problem. One key component, the MR damper mandrel, has been redesigned into a three-piece assembly which will facilitate assembly and reduce the cost of replacement of worn components. The remade parts will be delivered by April 19, and the prototype assembled. Testing will begin during the first week of May and is anticipated to be completed before the revised end date for Phase I, May 31, 2004.« less
  • Testing of the prototype valve began during this quarter. The objective of the first preliminary tests was to determine the pressure drop that can be created across the valve under different conditions of flow and pressure. As described in Quarterly Report 3, the system uses pneumatic pressure to activate a cylinder which in turn loads two hydraulic cylinders containing the MR fluid. Testing was preformed with no sensors or gauges other than the air pressure supply gauge. The valve was powered at 36 volts and drew about 3.5 amps. The valve held back the MR fluid at 30 psi. (Thismore » is the air pressure required to get the cylinders to move without any flow obstruction.) The air pressure was then increased gradually until the valve could no longer hold back the MR pressure and the cylinders moved slowly. The maximum air pressure that could be held without movement of the cylinders was 85 psi; however. as much as 30 psi of this pressure may be required to overcome stiction. Thus, the maximum pressure we were able to stop was somewhere between 55 and 85 psi of air. This translates into 1500 to 2330 psi MR fluid pressure. Based on the ratio of the piston area to that of the MR damper valve, this in turn translates to a force of 9,700 to 15,000 pounds. A force of this magnitude is what is required for operation of the damper under typical downhole conditions. Initial testing indicates that a valve capable of producing the required damping under the anticipated downhole conditions is technically feasible. The project is progressing, but behind schedule, and a four-month extension of Phase I is being requested. This extension will not alter the budget for Phase I and is expected to have no significant effect upon the overall program schedule or budget.« less
  • The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program entails modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype. The project continues to advance, but is behind the revised (14-month) schedule. Tasks 1-3 (Modeling, Specification and Design) are all essentially complete. The test bench for the Test and Evaluation (Tasks 4 & 5) has been designed and constructed. The design of themore » full-scale laboratory prototype and associated test equipment is complete and the components are out for manufacture. Barring any unforeseen difficulties, laboratory testing should be complete by the end of March, as currently scheduled. We anticipate the expenses through March to be approximately equal to those budgeted for Phase I.« less