Abstract:
The present invention relates generally to a rigless well intervention apparatus and method for well completion, recompletion, servicing, workover and intervention. Specifically, the present invention relates to a rigless well intervention apparatus and method for performing various well completion, recompletion, servicing, workover and intervention operations that pertains to a range of products, services and techniques whether designed to be run through, or conducted within, the production tubing of an oil or gas well, or not, ranging from the ability to operate within a restricted diameter tubular with live-well intervention when the tubing is in place to the ability to drill the well.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to a rigless well intervention apparatus and method. Specifically, the present invention relates to a rigless well intervention apparatus and method for performing various well workover and intervention operations that pertains to a range of products, services and techniques designed to be run through, or conducted within, the production tubing of an oil or gas well ranging from the ability to operate within a restricted diameter tubular with live-well intervention particularly, for running or pulling pipe on salt leaching, geothermal or suspended wells. 
       BACKGROUND OF THE INVENTION 
       [0002]    Oil well completion is a generic term used to describe the assembly of downhole tubulars and equipment required to enable the safe and efficient production from an oil or gas well. The point at which the completion process begins may depend on the type and design of the well. However, there are many options applied or actions performed during the construction phase of a well that have significant impact on the productivity of the well. 
         [0003]    The drilling completion hardware is used to optimize the production of hydrocarbons from the well. This may range from nothing but a packer on tubing above an openhole completion, sometimes referred to as barefoot completion, to a system of mechanical filtering elements outside of the perforated pipe, to a fully automated measurement and control system that optimizes reservoir economics without human intervention, sometimes referred to as an intelligent completion. 
         [0004]    The drilling completion hardware, typically, requires a drilling rig. A drilling rig is the machine used to drill a wellbore. In onshore operations, the rig includes virtually everything except living quarters. Major components of the rig include the mud tanks, the mud pumps, the derrick or mast, the drawworks, the rotary table or topdrive, the drilistring, the power generation equipment and auxiliary equipment. Offshore, the rig includes the same components as onshore, but not those of the vessel or drilling platform itself. The rig is sometimes referred to as the drilling package, particularly offshore. 
         [0005]    The rigless operation of a well completion process is defined as the well-intervention operation conducted with equipment and support facilities that precludes the requirement for a rig over the wellbore. By way of example, and without limitation, examples of rigless well completion operations are coiled tubing, slickline and snubbing activities. However, it can be appreciated by those skilled in the art that the use of the present invention provides for the use of a rigless operation that can encompass essentially all well completion processes. 
         [0006]    With respect to drilling a well, snubbing is the act of putting drillpipe into the wellbore when the blowout preventers (BOPs) are closed and pressure is contained in the well. Snubbing is necessary when a kick is taken, since well kill operations should always be conducted with the drillstring on bottom, and not somewhere up the wellbore. If only the annular blowout preventer has been closed, the drillpipe may be slowly and carefully lowered into the wellbore, and the blowout preventer itself will open slightly to permit the larger diameter tool joints to pass through. If the well has been closed with the use of ram blowout preventers, the tool joints will not pass by the closed ram element. Hence, while keeping the well closed with either another ram blowout preventer or the annular blowout preventer, the ram must be opened manually, then the pipe lowered until the tool joint is just below the ram, and then closing the ram again. This procedure is repeated whenever a tool joint must pass by a ram blowout preventer. In snubbing operations, the pressure in the wellbore acting on the cross-sectional area of the tubular can exert sufficient force to overcome the weight of the drillstring, so the string must be pushed or “snubbed” back into the wellbore. In ordinary stripping operations, the pipe falls into the wellbore under its own weight, and no additional downward force or pushing is required. 
         [0007]    Through-tubing well completion operations pertain to any reservoir or wellbore treatment performed through the tubing string. Through-tubing treatments are generally associated with live-well operations, thereby causing minimal interruption to production and eliminating the need to kill the well. 
         [0008]    Well workover and intervention operations pertain to a range of products, services and techniques designed to be run through, or conducted within, the production tubing of an oil or gas well. The term implies an ability to operate within a restricted diameter tubular and is often associated with live-well intervention since the tubing is in place. 
         [0009]    Typically, the well site is required to be rigged-up prior to production beginning. The rigging-up process includes setting up the substructure of the rig, setting up rig floor, setting up the mast or derrick, installing handrails, guardrails, stairs, walkways, and ladders, installing the power systems, rigging up the circulating system, installing the auxiliary equipment, and inspecting the rig. After the procedure is complete that required the rig, the rigging-down procedure is begun. The rigging down procedure is, typically, the opposite procedure from the rigging-up procedure. 
         [0010]    In setting up the substructure of the rig, the equipment is unloaded and positioned at or near the exact location that it will occupy during operations. The substructure is assembled, pinned together, leveled, and made ready for other rig components on the floor. Equipping the cellar begins but can be done throughout the rigging up process. Equipping the cellar includes welding on a drilling nipple to the conductor pipe and attaching a flow line. The cellar is a pit in the ground to provide additional height between the rig floor and the well head to accommodate the installation of blowout preventers, ratholes, mouseholes, and so forth. The cellar also collects drainage water and other fluids for disposal. 
         [0011]    Once the substructure is set in place, the process of setting up the rig floor begins. Setting up the rig floor begins by installing stairways and guardrails to allow access to the rig floor. Then, the drawworks is set in place and secured to the substructure. On mechanical rigs, the engines are set in place and the compound and associated equipment connected to the drawworks. On electric rigs, the electric cables or lines are strung to the drawworks. 
         [0012]    The bottom of the mast is raised to the rig floor and pinned in place. The crown section is then raised into place on the derrick stand. The “A-legs” are raised and pinned into place. The monkey board is pinned in place on the mast and all lines and cables are laid out to prevent tangling when the mast is raised. The mast is now ready to be raised. The engines are started, and the drilling line is spooled onto the drawworks drum. Once the mast has been raised and pinned, the remaining floor equipment can be set into place. If the rig has safety guylines, they must be attached to the anchors and properly tensioned prior to continuing the rigging up process. A derrick emergency escape device is installed on the mast. Handrails, guardrails, stairways, walkways, and ladders are installed where they are needed for safety and access. 
         [0013]    The power system is usually installed simultaneously with setting up the rig floor, because power is needed to operate the equipment. Today there are generally two types of rigs being used on land. A mechanical rig is powered by engines and compound. An electric rig is powered by engines and generators. This type supplies power to electric motors, which drive the machinery. All power cords, belts, and chains are connected to the machinery from their associated power source. Also, the fuel lines and tanks are hooked up, and the engines are started. 
         [0014]    Then, the circulating system is rigged up. Rigging up the circulating system requires that the mud tanks and mud pumps are set into the predetermined location. The mud lines are then connected and electric cords are strung. 
         [0015]    Thereafter, all remaining drilling and auxiliary equipment must be set into place and installed where needed. The catwalk and pipe racks are positioned and the pipe and drill collars are set on the racks. 
         [0016]    After production casing is run and cemented, the rig is taken down and moved to another site. The rigging down process is similar to, but the opposite of, the rigging up process. 
         [0017]    Wells eventually need maintenance or service on the surface or down-hole equipment. Working on an existing well to restore or increase oil and gas production is an important part of the petroleum industry. A well that is not producing to its full potential may require service or workover. 
         [0018]    Workover activities include one or more of a variety of remedial operations on a producing well to try to increase production. For example, sand cleanout operations are performed to remove buildup of sand in the wellbore. Repair is required for the liners and casing. The liners and casing are essentially the same and repair procedures are the same for both. Casing can be damaged by corrosion, abrasion, pressure, or other forces that create holes or splits. A packer is run down the well to locate the hole in the casing. Fluid is pumped into the casing above the packer. A loss of pressure indicates a hole in the casing. Examples of just some of the principal methods for repairing casing is squeeze cementing, patching a liner, replacing casing, adding a liner, and opening collapsed casing. 
         [0019]    Sidetracking is the workover term for drilling a directional hole to bypass an obstruction in the well that cannot be removed or causes damage to the well, such as a collapsed casing that cannot be repaired. Sidetracking is also done to deepen a well or to relocate the bottom of the well in a more productive zone, which is horizontally removed from the original well. To sidetrack, a hole called a window is made in the casing above the obstruction. The well is then plugged with cement below the window. Special drill tools, such as a whipstock, bent housing, or bent sub are used to drill off at an angle from the main well. This new hole is completed in the same manner as any well after a liner is set. 
         [0020]    Plug-back places a cement plug at one or more locations in a well to shut off flow from below the plug. Plug-back is also used before abandoning a well or before sidetracking is done. 
         [0021]    Generally, a pulling unit or production rig is a well-servicing outfit used in pulling rods and tubing from the well. The production rig is a portable servicing or workover unit, usually mounted on wheels and self-propelled. A well servicing unit consists of a hoist and engine mounted on a wheeled chassis with a self-erecting mast. A workover rig is basically the same, with the addition of a substructure with rotary, pump, pits, and auxiliaries to permit handling and working a drill string. 
         [0022]    Among the reasons for pulling tubing includes replacing a packer, locating a tubing leak, or plugged tubing. To service, repair, or replace the rods or pump, the sucker rod string must be pulled out of the hole. Pulling rods refers to the process of removing rods from the well. Running rods refers to the process of replacing rods in the well. 
         [0023]    To begin the process of pulling or running rods, the wellhead must be removed from the casing flange. The wellhead or casing head is a heavy, flanged steel fitting connected to the first string of casing. The casing head provides a housing for slips and packing assemblies, allows suspension of intermediate and production strings of casing, and supplies the means for the annulus to be sealed off. It may also be called a spool. 
         [0024]    The above background discussion provides examples where the rigless well intervention apparatus and method of the present invention can be used. The above discussion is not intended to be limiting, but rather, is meant to be exemplar. Thus, one skilled in the art will appreciate that the rigless well intervention apparatus and method can be adapted for use in many and varied applications, including applications not discussed above, but appreciated by those skilled in the art as being applicable applications of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The accompanying drawings which are incorporated in and constitute a part of the specification, illustrate a preferred embodiment of the invention and together with the general description of the invention given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. 
           [0026]      FIG. 1  is an elevation view of a preferred embodiment of the rigless well intervention apparatus encompassed by the present invention. 
           [0027]      FIG. 2  is an elevation view of the preferred embodiment of the rigless well intervention apparatus encompassed by the present invention at a 90 degree angle from the view in  FIG. 1 . 
           [0028]      FIG. 3  is an plan view of the preferred embodiment of the rigless well intervention apparatus encompassed by the present invention as illustrated in  FIGS. 1 and 2 . 
           [0029]      FIG. 4  is an plan view of the upper level of the preferred embodiment of the rigless well intervention apparatus encompassed by the present invention as illustrated in  FIGS. 1 ,  2  and  3 . 
           [0030]      FIG. 5  is an illustration of a preferred embodiment of the rigless well intervention apparatus encompassed by the present invention showing a landing joint about to engage a hanger. 
           [0031]      FIG. 6  is an illustration of the preferred embodiment of the rigless well intervention apparatus in  FIG. 5  showing the hanger being removed. 
           [0032]      FIG. 7  is an illustration of the preferred embodiment of the rigless well intervention apparatus in  FIGS. 5 and 6  showing the hanger being removed and the cylinders and gauges. 
           [0033]      FIG. 8  is an illustration of the preferred embodiment of the rigless well intervention apparatus in  FIGS. 5 ,  6  and  7  showing the hanger removed. 
           [0034]      FIG. 9  is an illustration of a preferred embodiment of the rigless well intervention apparatus encompassed by the present invention showing a spider on the second level with the spider in ant open position. 
           [0035]      FIG. 10  is an illustration of a preferred embodiment of the rigless well intervention apparatus encompassed by the present invention showing the spider on the second level as shown in  FIG. 9  with the spider in an engaged position. 
           [0036]      FIG. 11  is an illustration of a preferred embodiment of the rigless well intervention apparatus encompassed by the present invention showing the rigless well intervention apparatus being lifted and placed on a well. 
           [0037]      FIG. 12  is flow chart of a preferred embodiment of the rigless well intervention method encompassed by the present invention. 
           [0038]      FIG. 13  is flow chart of another preferred embodiment of the rigless well intervention method encompassed by the present invention. 
           [0039]      FIG. 14  is flow chart of another preferred embodiment of the rigless well intervention method encompassed by the present invention. 
       
    
    
       [0040]    The above general description and the following detailed description are merely illustrative of the generic invention, and additional modes, advantages, and particulars of this invention will be readily suggested to those skilled in the art without departing from the spirit and scope of the invention. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0041]    The rigless intervention apparatus of the present invention is a substructure frame created to handle pipe and perform many and varied well workover and intervention operations. Such operations can pertain to a range of products, services and techniques associated with running or pulling pipe, or alternately, associated with the servicing or repair of the production tubing or other aspects of an oil or gas well. The rigless intervention apparatus of the present invention is especially adapted for running or pulling pipe on salt leaching, geothermal, or suspended wells. 
         [0042]    The substructure frame of the rigless intervention apparatus and method of the present invention includes hydraulic jacks and strain gauges for accurately controlling the positioning and movement of the pipe or other well components. 
         [0043]    The rigless intervention apparatus of the present invention provides a moveable framework adapted for movement mechanically, hydraulically, using any type of fluid pressure, or any other way to move the parts of the frame to enable lifting or moving tubulars, pipe, and other components. In one embodiment, the framework of the rigless intervention apparatus of the present invention has three levels: a upper level, a mid level and a base level. The top level has a gallows-type device for lifting. The mid level has a spider elevator. And, the base level is configured to any height required to accommodate the ground covered. The rigless intervention apparatus of the present invention has a lifting capacity of several hundred tons. Strain gauges are incorporated into the rigless intervention apparatus of the present invention to determine and to monitor the exact weight to be lifted or being lifted. The strain gauges are preferably in operative association with or located in the lifting mechanism. However, it is appreciated by one skilled in the art that the strain gauges can be adapted for use with respect to any part of the rigless intervention apparatus of the present invention. Thus, the rigless intervention apparatus of the present invention can determine, for example, the weight of the pipe of the old string hanging on the hook, or, what the weight is before initiating the pull to make sure that the weigh of the string will not exceed the pulling weight. The rigless intervention method and apparatus of the present invention replaces the conventional rig and incorporates the ability to monitor the lifting process. 
         [0044]    Activities for which the rigless intervention apparatus of the present invention is adapted particularly includes, without limitation, running completions, running and pulling casing for measuring the cavern cavities, pulling damaged pipe, jacking of the hanger prior to pulling, drilling salt with a mud motor, repair cavity leakage by pumping synthetic resin, drilling a synthetic plug, testing with an inflatable plug system, change over of the P-Seals on the well head without pulling the casing, pull testing on the packer down hole, setting completion in tension, cavern acceptance testing, changing seals on the wellhead. Examples of the varied and different activities for which the rigless intervention apparatus of the present invention is adapted are jacking the hanger free, running pipe and running a control line. 
         [0045]    The rigless intervention apparatus of the present invention can be built, transported and lifted into place on the well head. 
         [0046]    The advantages of the rigless intervention apparatus of the present invention are varied and numerous. By way of example, and without limitation, the rigless intervention apparatus and method of the present invention is designed for leached activities, it is safe to operate, has low transportation cost, has low rig movement cost, has low cost during the rig-up and rig-down process, the capacity can be above a conventional workover rig, it has minimum equipment requirements, no highly qualified personnel are required, it has minimum certification requirements, and all operations are PC monitored. Additional features and advantages of the invention will be set forth in part in this description, and in part will become apparent from the description, or may be learned by practice of the invention. The features and advantages of the invention may be realized by means of the combinations and steps particularly pointed out in the appended claims. 
         [0047]    Reference will now be made in detail to the present preferred embodiments of the invention as described in the accompanying drawings. 
         [0048]      FIG. 1  is an elevation view of a preferred embodiment of the rigless well intervention apparatus  100  encompassed by the present invention. The rigless well intervention apparatus  100  comprises a base level  110 , an intermediate level  120  and an upper level  130 . The upper level  130  has a gallows structure  132  for lifting components. Also, the upper level  130  has a ladder  134  for accessing the upper level  130 . 
         [0049]      FIG. 2  is an elevation view of the preferred embodiment of the rigless well intervention apparatus  200  encompassed by the present invention. The rigless well intervention apparatus  200  in  FIG. 2  is shown at a 90 degree angle from the view in  FIG. 1 . The rigless well intervention apparatus  200  comprises a base level  210 , an intermediate level  220  and an upper level  230 . 
         [0050]      FIG. 3  is an elevation view of an embodiment of the cylinder  316 A,  316 B and strain gauge  318 A,  318 B arrangement of a preferred embodiment of the rigless well intervention apparatus  300  encompassed by the present invention. The rigless well intervention apparatus  300  is shown with a base level  310  and an intermediate level  320 . Intermediate between the base level  310  and the intermediate level  320  are a rotating member  311 A,  311 B, an exterior cylinder  312 A,  312 B, a cylinder mechanism  316 A,  316 B, a strain gauge  318 A,  318 B, a shaft  314 A,  314 B and a second rotating member  314 A,  314 B. 
         [0051]      FIG. 4  is an plan view of an upper level  402  of the preferred embodiment of the rigless well intervention apparatus  400  encompassed by the present invention. 
         [0052]      FIG. 5  is an illustration of a preferred embodiment of the rigless well intervention apparatus  500  encompassed by the present invention showing a landing joint  12  about to engage a hanger  14 . The landing joint  12  and the hanger  14  are disposed between the base level  510  and the intermediate level  520 . 
         [0053]      FIG. 6  is an illustration of the preferred embodiment of the rigless well intervention apparatus  600  in  FIG. 5  showing the hanger  12  being removed from the well head  16 .  FIG. 6  also illustrates the base level  610 , the intermediate level  620  and the upper level  630 . Between the base level  610  and the intermediate level  620 , the rotating member  611 , the exterior cylinder  312 , and the shaft  314  are shown. 
         [0054]      FIG. 7  is an illustration of the preferred embodiment of the rigless well intervention apparatus  700  in  FIGS. 5 and 6  showing the hanger  12  being removed from the well head  16  via the landing joint  14 . The intermediate level  720  is supported by the combination of the exterior cylinder  712 , the rod  714  and the rotating member  713 . Also illustrated is the connection  718 C in the cylinder  712  for the strain gauge. The rod  714  is shown extended from the cylinder  712 . 
         [0055]      FIG. 8  is an illustration of the preferred embodiment of the rigless well intervention apparatus  800  in  FIGS. 5 ,  6  and  7  showing the hanger  12  removed. Between the base level  810  and the intermediate level  820 , the rotating member  811 , the exterior cylinder  812 , and the shaft  814  are shown. The rod  814  is shown withdrawn into the cylinder  812 . 
         [0056]      FIG. 9  is an illustration of a preferred embodiment of the rigless well intervention apparatus encompassed by the present invention showing the spider  932  on the second level  920  and below the upper level  930 . The spider  932  is in a disengaged, open position. 
         [0057]      FIG. 10  is an illustration of a preferred embodiment of the rigless well intervention apparatus encompassed by the present invention showing the spider  1032  on the second level  1020  and below the upper level  1030 . The spider  1032  is in an engaged, closed position. 
         [0058]      FIG. 11  is an illustration of a preferred embodiment of the rigless well intervention apparatus  1100  encompassed by the present invention showing the rigless well intervention apparatus  1100  being lifted and placed on a well by a crane  18 . 
         [0059]      FIG. 12  is flow chart of a preferred embodiment of the rigless well intervention method  1200  encompassed by the present invention. The method is for performing various well completion, recompletion, servicing, workover and intervention operations that pertain to a range of products, services and techniques applied to a well having a wellbore, and particularly, associated with a pipe string. The method comprises the steps of maintaining a structure in association with the wellbore such that the structure has a maximum string pulling capacity  1202 , measuring the weight of the pipe string in the wellbore  1204 , determining whether the weight of the pipe string in the wellbore exceeds the maximum string pulling capacity of the structure  1206 , if the weight of the pipe string in the wellbore exceeds the maximum string pulling capacity of the structure then, terminating the pull of the pipe string in the wellbore  1208 , and, if the weight of the pipe string in the wellbore does not exceed the maximum string pulling capacity of the structure then, commencing the pull of the pipe string in the wellbore  1210 . 
         [0060]      FIG. 13  is flow chart of another preferred embodiment of the rigless well intervention method  1300  encompassed by the present invention for performing various well completion, recompletion, servicing, workover and intervention operations that pertains to a range of products, services and techniques applied to a well having a wellbore and a component associated with the well. The method comprising the steps of maintaining a structure in association with the wellbore such that the structure has a maximum lifting capacity  1302 , measuring the weight of the component associated with the well  1304 , determining whether the weight of the component associated with the well exceeds the maximum lifting capacity of the structure  1306 , if the weight of the component associated with the well exceeds the maximum lifting capacity of the structure then, terminating the lift of the component associated with the well  1308 , and if the weight of the component associated with the well does not exceed the maximum lifting capacity of the structure then, commencing the lift of the component associated with the well  1310 . 
         [0061]      FIG. 14  is flow chart of another preferred embodiment of the rigless well intervention method  1400  encompassed by the present invention for performing various well completion, recompletion, servicing, workover and intervention operations that pertains to a range of products, services and techniques applied to a well having a wellbore and a component associated with the well. The method comprising the steps of maintaining a structure in association with the wellbore such that the structure has a maximum lifting capacity  1402 , measuring the weight of the component associated with the well  1404 , determining whether the weight of the component associated with the well exceeds the maximum lifting capacity of the structure  1406 , if the weight of the component associated with the well exceeds the maximum lifting capacity of the structure then, terminating the lift of the component associated with the well  1408 , if the weight of the component associated with the well does not exceed the maximum lifting capacity of the structure then, commencing the lift of the component associated with the well  1410 , monitoring the weight of the component during the lift  1412 , if the weight of the component exceeds the maximum lifting capacity of the structure during the lifting process then, terminating the lift of the component and secure the component  1414 , and if the weight of the component does not exceed the maximum lifting capacity of the structure during the lifting process then, continuing the lift of the component to completion  1416 . 
         [0062]    Additional advantages and modification will readily occur to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus, and the illustrative examples shown and described herein. Accordingly, departures may be made from the details without departing from the spirit or scope of the disclosed general inventive concept.