1. Field of the Invention
The present invention relates to the art of earth boring. In particular, the invention relates to methods and apparatus for remotely controlling the operation of downhole tools.
2. Description of Related Art
In pursuit of deeply deposited economic minerals and fluids such as hydrocarbons, the art of earthboring involves many physical operations that are carried out remotely under hazardous and sometimes hostile conditions. For example, hydrocarbon producing boreholes may be more than. 25,000 ft. deep and have a bottom-hole pressure more than 10,000 psi and a bottom-hole temperature in excess of 300 F.
Transmitting power and control signals to dynamic tools working near the wellbore bottom is an engineering challenge. Some tools and circumstances allow the internal flow bore of a pipe or tubing string to be pressurized with water or other well working fluid. Sustained high pressure may be used to displace sleeves or piston elements within the work string. In other circumstances, a pumped circulation flow of working fluid along the pipe bore may be used to drive a downhole fluid motor or electric generator.
The transmission of operational commands to downhole machinery by coded sequences of pressure pulses carried along the wellbore fluid has been used to signal the beginning or ending of an operation that is mechanically executed by battery power such as the opening or closing of a valve. Also known to the prior art is the technique of using in situ wellbore pressure to power the operation of a mechanical element such a well packer or slip.
All of these prior art power and signal devices are useful in particular environments and applications. However, the challenges of deepwell drilling are many and diverse. New tools, procedures and downhole conditions evolve rapidly. Consequently, practitioners of the art constantly search for new and better devices and procedures to power or activate a downhole mechanism.
“Controllable fluids” are materials that respond to an applied electric or magnetic field with a change in their rheological behavior. Typically, this change is manifested when the fluids are sheared by the development of a yield stress that is more or less proportional to the magnitude of the applied field. These materials are commonly referred to as electrorheological (ER) or magnetorheological (MR) fluids. Interest in controllable fluids derives from their ability to provide simple, quiet, rapid-response interfaces between electronic controls and mechanical systems. Controllable fluids have the potential to radically change the way electromechanical devices are designed and operated.
MR fluids are non-colloidal suspensions of polarizable particles having a size on the order of a few microns. Typical carrier fluids for magnetically responsive particles include hydrocarbon oil, silicon oil and water. The particulates in the carrier fluid may represent 25-45% of the total mixture volume. Such fluids respond to an applied magnetic field with a change in rheological behavior. Polarization induced in the suspended particles by application of an external field causes the particles to form columnar structures parallel to the applied field. These chain-like structures restrict the motion of the fluid, thereby increasing the viscous characteristics of the suspension.
ER systems also are non-colloidal suspensions of polarizable particles having a size on the order of a few microns. However, with applied power, some of these fluids have a volume expansion of 100%. Some formulations, properties and characteristics of controllable fluids have been provided by the authors Mark R. Jolly, Jonathan W. Bender and J. David Carlson in their publication titled Properties and Application of Commercial Magnetorheological Fluids, SPIE 5th Annual Int. Symposium on Smart Structures and Materials, San Diego, Calif., March, 1998, the body of which is incorporated herein by reference.
It is, therefore, an object of the present invention to provide a new downhole operational tool in the form of electrically responsive polymers as active tool operation and control elements.
Also an object of the present invention is the provision of a downhole well tool having no moving fluid control elements.
Another object of the present invention is a disappearing flow bore plug that is electrically ejected from a flow obstruction position.
The present invention provides a method and apparatus for actuation of a downhole tool by placing an electroactive fluid in a container within the tool where the fluid becomes either highly viscous or a solid when a small magnetic field is applied. After deactivation or removal of an electromagnetic field current, the fluid becomes much less viscous. At the lower viscosity value, the fluid may be induced to flow from a mechanical restraint chamber thereby permitting the movement of a slip setting piston. Such movement of a setting piston may be biased by a mechanical spring, by in situ wellbore pressure or by pump generated hydraulic pressure, for example.
In another application that is similar to the first, an ER polymer is positioned to expand against setting piston elements when an electromagnetic field is imposed. The polymer expansion may be applied to displace cooperating wedge elements, for example.
In yet another application, an MR fluid may be used to control a failsafe lock system wherein a fluid lock keeps a valve blocking element open against a mechanical spring bias until an electromagnetic power current is removed. When the current is removed and the magnetic field decreases, the MR fluid is expressed from a retention chamber under the bias of the spring to allow closure of the valve blocking element.
Under some operational circumstances, it is necessary to temporarily but completely block the flow bore of a production tube by such means as are characterized as a “disappearing” plug. Distinctively, when the disappearing plug is removed to open the tubing flow bore, little or no structure remains in the flow bore to impede fluid flow therein. To this need, the invention provides a bore plug in the form of a thin metal or plastic container in the shape of a short cylinder, for example, filled with MR fluid. The MR fluid filled cylinder may be caged across the tubing flow bore in a retainer channel. An electromagnet coil is positioned in the proximity of the retainer channel. At the appropriate time, the coil is de-energized to reduce the MR fluid viscosity thereby collapsing from the retainer channel and from a blocking position in the tubing bore.
An ER fluid may be used as a downhole motor or linear positioning device. Also, an ER fluid may be used as a direct wellbore packing fluid confined within a packer sleeve and electrically actuated to expand to a fluid sealing annulus barrier.
For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawing wherein:
Referring to
One face of the piston 16 is a load bearing wall of a wellbore pressure chamber 32. One or more flow ports 34 through the casement wall 10 keep the chamber 32 in approximate pressure equilibrium with the wellbore fluid pressure. The opposing face of piston 16 is a load bearing wall of the electrically controlled fluid chamber 30. An orifice restrictor 42 is another load bearing wall of the controlled fluid chamber 30 and is designed to provide a precisely dimensioned orifice passageway 40 between the restrictor and the piston 16 sleeve.
Constructed into the outer perimeter of the casement 10 adjacent to the controlled fluid chamber 30 is an electromagnet winding 20. Typically, the winding is energized by a battery 24 carried within the tool, usually near an axial end of the tool. A current controller 22 in the electromagnet power circuit comprises, for example, a signal sensor and a power switching circuit. The signal sensor may, for example, be responsive to a coded pulse sequence of pressure pulsations transmitted by well fluid as a carrier medium.
Opposite of the orifice 40 and restrictor 42 is a low pressure chamber 36. Frequently, the low pressure chamber is a void volume having capacity for the desired quantity of controlled fluid as is expected to be displaced from the chamber 30. Often, the tool is deployed with ambient pressure in the chamber 36, there being no effort given to actively evacuate the chamber 36. However, downhole presure may be many thousands of pounds per square inch. Consequently, relative to the downhole pressure, surface ambient pressure is extremely low.
As the tool is run into a well, the winding 20 is energized to polarize the controllable fluid in the chamber 30 and prevent bypass flow into across the restriction 40 into the low pressure chamber 36. When situated at the desired depth, the coil is de-energized thereby permitting the controllable fluid to revert to a lower-viscosity property. Under the in situ pressure bias in chamber 32, the slip actuating piston 16 displaces the controllable fluid from the chamber 30 into the low pressure chamber 36. In the process, the actuating piston 16 drives the slip wicker 17 against the conical face 19 of the actuating cone 18 thereby forcing the slip wicker radially outward against the surrounding case wall.
With respect to the
Also pivotally connected to the flapper element at the hinge joint 51 is piston rod 53 extended from a piston element 60. The piston translates within a chamber 62. On the rod side of the chamber space is a coil spring 64 that biases the piston away from the hinge axes and toward the head end 66 of the chamber space. The head end 66 of the chamber 62 is charged with controllable fluid and surrounded by an electromagnet coil 68. The piston may or mat not be perforated between the head face and rod face by selectively sized orifices that will permit the controllable fluid to flow from the head chamber 66 into the rod chamber under the displacement pressure bias of the spring 64 when the coil is de-energized. As shown with the rod hinge 51 on the inside of the flapper hinge 58, advancement of the piston 60 into the head chamber 66 will rotate the flapper 56 away from the closure seat 54 to open the flow bore 52. The opposite effect may be obtained by placing the rod hinge 51 on the outside of the flapper hinge 58.
The invention embodiment of
Although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that the description is for illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those of ordinary skill in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described and claimed invention.
The present application is a continuation of U.S. patent application Ser. No. 09/916,617 filed Jul. 27, 2001, which issued as U.S. Pat. No. 6,568,470 on May 27, 2003.
Number | Name | Date | Kind |
---|---|---|---|
2417850 | Winslow | Mar 1947 | A |
2505049 | Keller | Apr 1950 | A |
2575360 | Rabinow | Nov 1951 | A |
2661596 | Winslow | Dec 1953 | A |
2661825 | Winslow | Dec 1953 | A |
2663809 | Winslow | Dec 1953 | A |
3047507 | Winslow | Jul 1962 | A |
3659648 | Cobbs | May 1972 | A |
3842917 | Wisotsky | Oct 1974 | A |
4029158 | Gerrish | Jun 1977 | A |
4992360 | Tsuruta et al. | Feb 1991 | A |
5146050 | Strozeski et al. | Sep 1992 | A |
5158109 | Hare, Sr. | Oct 1992 | A |
5167850 | Shtarkman | Dec 1992 | A |
5277282 | Umemura | Jan 1994 | A |
5284330 | Carlson et al. | Feb 1994 | A |
5291956 | Mueller et al. | Mar 1994 | A |
5404956 | Bohlen et al. | Apr 1995 | A |
5452745 | Kordonsky et al. | Sep 1995 | A |
5893413 | Lembcke et al. | Apr 1999 | A |
5956951 | O'Callaghan | Sep 1999 | A |
6019201 | Gordaninejad et al. | Feb 2000 | A |
6158470 | Ivers et al. | Dec 2000 | A |
6257356 | Wassell | Jul 2001 | B1 |
6433991 | Deaton et al. | Aug 2002 | B1 |
6568470 | Goodson et al. | May 2003 | B2 |
6619388 | Dietz et al. | Sep 2003 | B2 |
Number | Date | Country |
---|---|---|
14042 | Aug 1980 | EP |
20091 | Dec 1980 | EP |
0581476 | Feb 1994 | EP |
2039567 | Aug 1980 | GB |
2050466 | Jan 1981 | GB |
2352464 | Jan 2001 | GB |
WO9922383 | May 1999 | WO |
Number | Date | Country | |
---|---|---|---|
20030192687 A1 | Oct 2003 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 09916617 | Jul 2001 | US |
Child | 10444857 | US |