Abstract:
A mobile land rig for use in wellbore operations. The mobile land rig, in certain aspects, has a vehicle; an erectable mast; winch apparatus (e.g., one or two winches); and electric motor apparatus for powering the winch apparatus. In one aspect there are two winches and one electric motor powers both winches. This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 CFR 1.72(b).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is directed to well servicing rigs; methods of their use; in certain particular aspects to such rigs with electrical motor(s) as power apparatus, e.g., for a winch or winches; and in other particular aspects, to such rigs with a single electric motor to power two rig winches. 
         [0003]    2. Description of Related Art 
         [0004]    Well servicing rigs, which are not used to drill a wellbore, perform a variety of operations after an oil or gas well has been drilled to get a well ready for production; for example, and not by way of limitation: logging operations; swabbing operations; operations involving the insertion of pipe or tubing into the well; and a perforation operation to perforate tubing. 
         [0005]    A typical well servicing system, disclosed in U.S. Pat. No. 6,003,598, has a mobile vehicle/carrier with a collapsible mast or derrick which may be hydraulically raised and lowered by means of hydraulic pistons. A first winch and cable as provided near the crown of the derrick perform functions such as manipulating joined pipe segments if required. A second winch assembly and a drum having on it a line and item or tool, e.g., a conductive wireline with a logging instrument to be lowered into the well to permit logging. 
         [0006]    Established producing wells are often “worked over” or serviced from time to time, including replacing downhole equipment or lowering or raising objects into the wellbore such as casing, tubing, rods, tools, etc. When such service operations become necessary, often a portable workover rig is used which can be moved to the well site and set up. Certain known workover rigs have a derrick or mast which supports pulleys or block and tackle arrangements; a mainline drum about which a heavy cable is wound and the free end connected over a crown block and connected to a traveling block. By rotating the drum, the traveling block is raised or lowered with the drilling mast as is necessary. Another drum, called a sandline drum (not used with the traveling block), has a line wound about it which goes up over the crown block and is then connected to an object such as a swab mandrel which is to be lowered into the well bore to a selected depth. In many conventional workover rigs the mainline drum and the sandline drum are each driven by a dedicated separate motor, typically e.g. a system with diesel-powered engines and associated drive shafts, clutches, right angle gear boxes, chains, and sprockets; or hydraulic motors. 
         [0007]    Providing hydraulic power fluid to well servicing rigs and workover rigs has presented a variety of problems. When hydraulic systems leak, hydraulic fluid is spilled polluting the environment. Hydraulically-powered motors and apparatuses, especially in multi-motor systems, are relatively heavy; relatively noisy; require a large amount of space on a rig; and are relatively complex and expensive to operate and maintain. Diesel-powered engine systems for servicing rigs and workover rigs present issues with excessive weight, power efficiency, safety concerns, excessive noise, inefficient manually operated-braking systems, diesel fume pollution and relatively high maintenance costs. 
         [0008]    The prior art discloses a variety of mobile rigs, well servicing rigs, workover rigs, and components of them; for example, and not by way of limitation, the following U.S. Patents present exemplary systems and components thereof: U.S. Pat. Nos. 2,704,653; 2,847,098; 3,109,523; 3,670,831; 3,734,210; 3,994,350; 4,257,578; 4,290,495; 4,371,046; 4,432,532; 4,478,291; 4,555,092; 4,591,006; 4,756,366; 5,094,302; 5,794,723; and 7,249,629—these patents all incorporated fully herein for all purposes. 
         [0009]    The present inventor has recognized the need for low weight, low cost, more efficient, safer, less noisy, environmentally-friendly mobile rigs for well servicing and workover, in certain aspects, with advanced control systems and/or improved braking performance. The present inventor has recognized the need for such rigs which are effective and efficient, yet relatively simple. The present inventor has recognized the need for such rigs with motors that are not hydraulically powered and rigs that are not powered through complicated mechanical drive arrangements. The present inventor has recognized the need for providing an electrical motor powered hoisting and braking system for the main drum and sand line drum, combined with an advanced electronic computerized control system in well servicing rig systems that are lighter quieter, safer, more efficient, and friendlier to the environment than conventional mechanical or hydraulically powered well servicing rigs. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    The present invention, in certain aspects, discloses a mobile rig for well operations which has apparatuses, e.g. winch apparatus, powered by an electric motor or motors. In certain aspects, such a rig has one or more single-board computers in a control system and/or one or more programmable logic controllers or a similar type of electronic control devices. 
         [0011]    In certain particular aspects, the present invention teaches a mobile rig with a single electric motor which provides power for a main winch apparatus and for a sandline winch apparatus. In certain aspects, the single electric motor also provides the primary braking function for each of the winch apparatuses. 
         [0012]    In certain aspects, the present invention discloses a mobile rig with a single, dual-shaft electric motor which provides power to two winch systems. 
         [0013]    In certain aspects, the present invention teaches a mobile rig with an electric motor or motor which is engaged for both hoisting operations and for lowering items into a wellbore, providing control of a load being lowered into a wellbore. 
         [0014]    In certain aspects, the present invention teaches a mobile rig with a drawworks powered by its own permanent magnet electric motor and a sandline winch powered by its own permanent magnet electric motor. 
         [0015]    In certain aspects, the present invention discloses a rig which employs electric power for a variety of rig functions, e.g., but not limited to, winch operation, mast raising, and outrigger deployment; rigs in which all such operations are powered by electric motors; and/or with a motor or motors that provide control while lowering a load and/or a braking function. 
         [0016]    Accordingly, the present invention includes features and advantages which are believed to enable it to advance mobile rig technology. Characteristics and advantages of the present invention described above and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments and referring to the accompanying drawings. 
         [0017]    Certain embodiments of this invention are not limited to any particular individual feature disclosed here, but include combinations of them distinguished from the prior art in their structures, functions, and/or results achieved. Features of the invention have been broadly described so that the detailed descriptions that follow may be better understood, and in order that the contributions of this invention to the arts may be better appreciated. There are, of course, additional aspects of the invention described below and which may be included in the subject matter of the claims to this invention. Those skilled in the art who have the benefit of this invention, its teachings, and suggestions will appreciate that the conceptions of this disclosure may be used as a creative basis for designing other structures, methods and systems for carrying out and practicing the present invention. The claims of this invention are to be read to include any legally equivalent devices or methods which do not depart from the spirit and scope of the present invention. 
         [0018]    What follows are some of, but not all, the objects of this invention. In addition to the specific objects stated below for at least certain embodiments of the invention, there are other objects and purposes which will be readily apparent to one of skill in this art who has the benefit of this invention&#39;s teachings and disclosures. It is, therefore, an object of at least certain preferred embodiments of the present invention to provide: 
         [0019]    New, useful, unique, efficient, non-obvious electrically-powered mobile rig systems for well operations and methods of their use; 
         [0020]    Such systems and methods which employ multiple electric motors or a single electric motor, and, in one particular aspect, a rig with a single electric motor to operate two winches; and 
         [0021]    Such systems and methods which significantly reduce or eliminate leakage of hydraulic fluids. 
         [0022]    The present invention recognizes and addresses the problems and needs in this area and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention&#39;s realizations, teachings, disclosures, and suggestions, other purposes and advantages will be appreciated from the following description of certain preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent&#39;s object to claim this invention no matter how others may later attempt to disguise it by variations in form, changes, or additions of further improvements. 
         [0023]    The Abstract that is part hereof is to enable the U.S. Patent and Trademark Office and the public generally, and scientists, engineers, researchers, and practitioners in the art who are not familiar with patent terms or legal terms of phraseology to determine quickly from a cursory inspection or review the nature and general area of the disclosure of this invention. The Abstract is neither intended to define the invention, which is done by the claims, nor is it intended to be limiting of the scope of the invention in any way. 
         [0024]    It will be understood that the various embodiments of the present invention may include one, some, or all of the disclosed, described, and/or enumerated improvements and/or technical advantages and/or elements in claims to this invention. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0025]    A more particular description of embodiments of the invention briefly summarized above may be had by references to the embodiments which are shown in the drawings which form a part of this specification. These drawings illustrate certain preferred embodiments and are not to be used to improperly limit the scope of the invention which may have other equally effective or legally equivalent embodiments. 
           [0026]      FIG. 1A  is a top perspective view of a system according to the present invention. 
           [0027]      FIG. 1B  is an enlarged perspective view of part of the system of  FIG. 1A . 
           [0028]      FIG. 1C  is an enlarged perspective view of part of the system of  FIG. 1A . 
           [0029]      FIG. 1D  is a top view of part of the system of  FIG. 1A . 
           [0030]      FIG. 1E  is a partial cross-section view of part of the system of  FIG. 1A . 
           [0031]      FIG. 1F  is a partial cross-section view of part of the system of  FIG. 1A . 
           [0032]      FIG. 1G  is a partial cross-section view of part of the system of  FIG. 1A . 
           [0033]      FIG. 2A  is a perspective view of a system according to the present invention. 
           [0034]      FIG. 2B  is a side view of the system of  FIG. 2A . 
           [0035]      FIG. 2C  is a top perspective view of the system of  FIG. 2A . 
           [0036]      FIG. 2D  is a top view of the system of  FIG. 2A . 
           [0037]      FIG. 2E  is an enlarged top view of part of the system as shown in  FIG. 2D . 
           [0038]      FIG. 2F  is a perspective view of part of the system as shown in  FIG. 2A . 
           [0039]      FIG. 2G  is a partial cross-section view of part of the system as shown in  FIG. 2A . 
           [0040]      FIG. 2H  is a partial cross-section view of part of the system as shown in  FIG. 2A . 
           [0041]      FIG. 2I  is a partial cross-section view of part of the system as shown in  FIG. 2A . 
           [0042]      FIG. 3A  is a side view of a system according to the present invention. 
           [0043]      FIG. 3B  is a top view of the system of  FIG. 3A . 
           [0044]      FIG. 4  is a side schematic view of a system according to the present invention. 
       
    
    
       [0045]    Presently preferred embodiments of the invention are shown in the above-identified figures and described in detail below. Various aspects and embodiments of the invention are described below are some are set out in the dependent claims. Any combination of aspects and/or features described below or shown in the dependent claims can be used except where such aspects and/or features are mutually exclusive. It should be understood that the appended drawings and description herein are of preferred embodiments and are not intended to limit the invention or the appended claims. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. In showing and describing the preferred embodiments, like or identical reference numerals are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness. 
         [0046]    As used herein and throughout all the various portions (and headings) of this patent, the terms “invention”, “present invention” and variations thereof mean one or more embodiment, and are not intended to mean the claimed invention of any particular appended claim(s) or all of the appended claims. Accordingly, the subject or topic of each such reference is not automatically or necessarily part of, or required by, any particular claim(s) merely because of such reference. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0047]      FIGS. 1A-1G  show a system  10  according to the present invention which includes a vehicle with a trailer  12  moved by a truck  14  and a mast  16  which can be raised from the trailer  12  to an erected position as shown in  FIG. 1A . Levelling jacks  18  support the trailer  12 . Optionally, no separate truck is used and the rig is self-propelled. 
         [0048]    An electric motor  20  provides power to operate a main winch  30  (also called a drawworks) and a sandline winch  40 . The motor  20  has two drive shafts, with one shaft extending from each end of the motor. One drive shaft  21  drives the main drum winch  30  via a gear system  32 . Optionally, a chain drive system is used. Another drive shaft  22  drives the sandline winch via a chain drive system  42 . A shiftable cutout coupling  23  selectively couples the drive shaft  21  to a shaft  37   a  of the gear system  32 . A housing  39  encloses the gears and shafts. 
         [0049]    A shiftable cutout coupling  24  selectively couples the drive shaft  22  to a shaft  44  of the chain drive system  42 . The gear system  32  includes intermeshed gears  35   a - 35   f  on shafts  38   a - 38   d , respectively, which drive a drive shaft  36  of the main drum winch  30 . The chain drive system  42  drives a drive shaft  46  of the sandline winch  40 . The chain drive system  42  has a chain  45  on sprockets  46   a ,  46   b  mounted, respectively, on the shaft  44  and a shaft  48 . A housing  49  partially encloses the chain  45 . The system  10  includes a blowout preventer control cabinet  11 ; an AC drive compartment  13 ; and a water cooled resistor tank  11  for removing the power (heat) generated during braking functions with the motor  20 . 
         [0050]    In one particular aspect, the motor  20  is a 1250 horsepower AC induction motor which provides a main winch hoisting capacity of 500 horsepower and a lowering capacity of 1250 horsepower. In other particular aspects, the motor&#39;s horsepower is between 800 horsepower to 1500 horsepower. Such a motor can provide controlled lowering of a load, e.g. up to 250,000 pounds, 113,636 kilograms. Any system according to the present invention can have such an electric motor or any other suitable electric motor. 
         [0051]    Comparing the system  10  in one particular comparison to a traditional rig with two separate hydraulically powered motors, one for each winch (e.g. 500 horsepower motors) and using a 1250 horsepower AC motor with the system  10 , it is anticipated that the system  10  will achieve a tripping in time of 22 seconds, and a tripping out time of 30 seconds (total tripping time 52 seconds); whereas with the traditional system tripping in time is 26 seconds, tripping out time is 55 seconds, for a total tripping time of 81 seconds. (“Tripping in time” is the time required to lower tools, tubing, or other well components approximately sixty feet into the hole and “tripping out time” is the time required to raise tools, tubing, or other well components approximately sixty feet up out of the hole.) 
         [0052]      FIGS. 2A-2I  show a system  100  according to the present invention which in some aspects is like the system  10 ,  FIG. 1A  (like numerals indicate like parts). A motor  120 , similar to the motor  20 ,  FIG. 1A , has a single drive shaft  122  which drives both the gear system  32  and the chain drive system  42 , thus a single motor drive shaft drives the main winch  30  and the sandline winch  40 . 
         [0053]    A coupling  102  couples the motor drive shaft  122  to the drive shaft  37   a  of the gear system  32  and a shifting mechanism  104  selectively couples the drive shaft of the gear system  32  to the drive shaft  44  of the chain drive system  42 .  FIG. 2G  shows the shifting mechanism  104  in a neutral position (engaging neither splines  106  on the shaft  37   a  nor splines  108  on the shaft  44 ).  FIG. 2H  shows the system with the main winch  30  (drawworks) engaged; the shifting mechanism  104  has engaged the splines  106  on the shaft  37   a .  FIG. 2I  shows the system with the sandline winch  40  engaged; the shifting mechanism  104  has engaged the splines  108  on the shaft  44 . 
         [0054]      FIGS. 3A and 3B  show a system  200  according to the present invention which includes a truck  202  that pulls a trailer  204 . An erectable mast  206  initially rests on the trailer  204 . The trailer  204  includes outrigger levelling jacks  208 . The trailer  204  supports a main drum or drawworks winch  210  and a sandline winch  220 . In one particular aspect, the mast is raised by a system ST (shown schematically) which has a small electrically-powered winch or an electrically-powered ball screw system BC. A system SY (shown schematically) with an electric motor raises and lowers the outrigger levelling jacks  208 . Optionally, the system SY includes an electrically operated ball screw system BR (shown schematically) built into the outrigger system. 
         [0055]    In one aspect, the main drum winch  210  has an internal electric motor system and the sandline winch  220  has an internal electric motor system. In one aspect the motors are AC permanent magnet motors (which may be the case for any motor in any system according to the present invention) with an AC drive system  250 . 
         [0056]    The AC drive system converts DC power to variable frequency AC power and includes a cooling unit  252  and an interface panel  254  for the cooling unit. In the cooling unit, water or forced air cools the resistors in a bank  218  that become hot while burning off the power developed during the motor&#39;s braking function. The AC motors can “brake” the load during load lowering or stopping. The AC motor simply acts like a generator while braking the load. As it acts like a generator, it produces power which is burned off through the bank of resistors. Such a system has no brake pads or brake shoes and no physical exertion is performed by a mobile rig operator to try to manually brake the load through long lever handles and mechanical linkage to brake bands. 
         [0057]    According to the present invention, the computerized control system provides signals to the AC motor to safely determine the motor speed and braking activity. The panel  254  is mounted to the floor of the trailer and includes electrical switch gear and control relays for operating the resistor cooling unit  252  and/or air blowers for cooling off the resistor bank. It communicates with temperature sensors associated with the resistor bank. 
         [0058]    A system with the blowout preventer panel  214  has control valves and gages which close the blowout preventer, e.g. in the event of an undesirable escape of gas (blowout) from the wellbore. 
         [0059]    An operator panel  222 , in communication with the apparatuses, winches, and devices of the system  200 , allows an operator to perform the various functions of the system  200 . 
         [0060]    The electric motors  230 ,  240  may, according to the present invention, be any suitable electric motor (as may be true for any system according to the present invention) including, but not limited to: AC induction motors; permanent magnet motors; printed circuit board permanent magnet motors; or direct current (DC) motors. 
         [0061]    Power is supplied to the motors  230 ,  240  from a power source  260  which may include (as is true for powering any motor of any system according to the present invention): local utility power; power from batteries; power from a power storage device or facility; and/or one or more independent engine generator units. 
         [0062]      FIG. 4  shows schematically a system  300  according to the present invention which has a truck  302  with a trailer  304  having an erectable mast  306  and levelling jacks  308 . A system operator  310  in a cabin  312  controls the various apparatuses, winches, and functions of the system  300  via a control system  314 . A system  324  raises the mast  306 . 
         [0063]    The system  300  has a main winch  320 , a sandline winch  330 , and an electric motor  340  which provides power for both winches. Appropriate lines  331 ,  332  around appropriate sheaves  333 - 335 , support and move various items, e.g. tubing  336  and/or tool  337  in a wellbore  338 . 
         [0064]    Power for the electric motor  340  is provided from a power source  350 . The electric motor  340  can run both winches. The levelling jacks  308  and the system  324  can include electrically operated ball screw units. Such a system may have one or some, in any possible combination, of the following: 
         [0065]    The present invention, therefore, provides in some, but not in necessarily all, embodiments a mobile land rig for use in wellbore operations, the mobile land rig including: a vehicle; an erectable mast on the vehicle; winch apparatus on the vehicle; and electric motor apparatus on the vehicle for powering the winch apparatus. Such a mobile land rig may have one or some, in any possible combination, of the following: the winch apparatus including a main winch and a sandline winch; the electric motor apparatus is a single electric motor; the winch apparatus includes a main winch and a sandline winch, the electric motor apparatus is a single electric motor, both the main winch and the sandline winch powered by the single electric motor; the single electric motor has two drive shafts, a first drive shaft and a second drive shaft, the first drive shaft for driving the main winch, and the second drive shaft for driving the sandline winch; the single electric motor has a single drive shaft, the main winch driven by the single drive shaft, and the sandline winch driven by the single drive shaft; shifting mechanism for selectively driving the main winch or the sandline winch; the mobile land rig is a well servicing rig or a workover rig; the electric motor apparatus provides braking while the winch apparatus lowers a load; mast erection apparatus which is electrically powered; the mast erection apparatus includes an electric winch system; vehicle levelling apparatus which is electrically powered; the vehicle levelling apparatus includes an electrically-operated ball screw unit; a computerized control system for controlling the electric motor apparatus; the electric motor apparatus is at least one electric motor which is one of AC induction motor, DC motor, permanent magnet motor, and a printed circuit board permanent magnet motor; a power source for the electric motor apparatus; wherein the power source is one of local utility, battery, power storage apparatus, and generator; and/or a control system in controlling communication with the electric motor apparatus and the winch apparatus, and an operator panel in communication with the control system whereby an operator can control the electric motor apparatus and the winch apparatus. 
         [0066]    The present invention, therefore, provides in some, but not in necessarily all, embodiments a mobile land rig for use in wellbore operations, the mobile land rig including: a vehicle; an erectable mast on the vehicle; winch apparatus on the vehicle; electric motor apparatus on the vehicle for powering the winch apparatus and for providing braking while the winch apparatus lowers a load; wherein the winch apparatus includes a main winch and a sandline winch; the electric motor apparatus is a single electric motor; both the main winch and the sandline winch powered by the single electric motor; shifting mechanism for selectively driving the main winch or the sandline winch; a computerized control system for controlling the electric motor apparatus and the winch apparatus; a power source for the electric motor apparatus; and an operator panel in communication with the control system whereby an operator can control the electric motor apparatus and the winch apparatus. Such a mobile land rig may have one or some, in any possible combination, of the following: the single electric motor has two drive shafts, a first drive shaft and a second drive shaft, the first drive shaft for driving the main winch, and the second drive shaft for driving the sandline winch. 
         [0067]    The present invention, therefore, provides in some, but not in necessarily all, embodiments a method for performing wellbore operations with a mobile land rig, the method including: erecting a mast on a vehicle of a mobile land rig, the mobile land rig including winch apparatus on the vehicle and electric motor apparatus on the vehicle for powering the winch apparatus; and winching an item with the winching apparatus. 
         [0068]    The present invention, therefore, provides in some, but not in necessarily all, embodiments a winch system for a mobile land rig, the winch system including winch apparatus mountable on a vehicle of a mobile land rig, and electric motor apparatus mountable on the vehicle in driving relationship with the winch apparatus for powering the winch apparatus. 
         [0069]    The present invention, therefore, provides in some, but not in necessarily all, embodiments a method for winching an item on a mobile land rig, the method including: attaching the item to a winch apparatus, the winch apparatus mounted on a vehicle of a mobile land rig; and winching the item with the winch apparatus, the winch apparatus powered by electric motor apparatus. 
         [0070]    In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein and those covered by the appended claims are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited in any of the following claims is to be understood as referring to the step literally and/or to all equivalent elements or steps. The following claims are intended to cover the invention as broadly as legally possible in whatever form it may be utilized. The invention claimed herein is new and novel in accordance with 35 U.S.C. § 102 and satisfies the conditions for patentability in § 102. The invention claimed herein is not obvious in accordance with 35 U.S.C. § 103 and satisfies the conditions for patentability in § 103. This specification and the claims that follow are in accordance with all of the requirements of 35 U.S.C. § 112. The inventor may rely on the Doctrine of Equivalents to determine and assess the scope of the invention and of the claims that follow as they may pertain to apparatus not materially departing from, but outside of, the literal scope of the invention as set forth in the following claims. All patents and applications identified herein are incorporated fully herein for all purposes. What follows are some of the claims for some of the embodiments and aspects of the present invention, but these claims are not necessarily meant to be a complete listing of nor exhaustive of every possible aspect and embodiment of the invention.