Patent Publication Number: US-2010122809-A1

Title: Rotating high-pressure pumping head

Description:
CROSS REFERENCES TO RELATED APPLICATION 
     Priority of U.S. Provisional Patent Application Ser. No. 61/137,516 filed Jul. 31, 2008, incorporated herein by reference, is hereby claimed. 
    
    
     STATEMENTS AS TO THE RIGHTS TO THE INVENTION MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     None 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to a pumping assembly for use in connection with oil and/or gas wells. More particularly, the present invention pertains to a pumping assembly that is capable of conveying fluids (including solids-laden fluids) pumped into oil and/or gas wells at high pressure including, without limitation, fluids pumped during hydraulic fracturing and other stimulation operations. More particularly still, the present invention pertains to a versatile pumping assembly that is capable conveying fluids (including solids-laden fluids) pumped into oil and/or gas wells at high pressure, while permitting pipe rotation. 
     2. Brief Description of the Prior Art 
     It is frequently beneficial to pump fluids into oil and/or gas wells at high pressure. One common operation involving the high pressure pumping of fluids into oil and/or gas wells is known as hydraulic fracturing. 
     Hydraulic fracturing is a method used to create fractures that extend from a well bore into surrounding rock formations penetrated by said well bore. Such fractures are typically held open by at least one material, commonly referred to as “proppant”; although many different materials can be used, proppant typically consists of grains of sand, ceramic beads or other similar material that can be pumped into the fractures and prevent such fractures from closing. 
     Generally, the technique of hydraulic fracturing is used to increase or restore the rate at which fluids, such as oil, gas or water, can be produced from a well. By creating fractures within productive down hole formations, the reservoir surface area in communication with the well bore is increased. In addition to hydraulic fracturing operations, other operations routinely involve the pumping of fluids into oil and/or gas wells at high pressure including, without limitation, pumping of acid and/or other chemicals. 
     During such pumping operations, a pumping “head” assembly is typically installed at or near the rig floor on a drilling rig and suspended over a well. Generally, the pumping head assembly serves as an intermediate connection point or conduit between the fluid source (such as, for example, storage tanks and associated pumping equipment), and the drill pipe, work string or other tubular goods that extends into the well bore. 
     Conventional pumping head assemblies used for pumping fluids into a well, especially at elevated pressures (such as during hydraulic fracturing and similar operations) suffer from a number of very significant limitations. Such conventional equipment typically comprises a collection of valves, pump-in subs, and swiveled pipe sections commonly referred to as “chicksans.” However, such conventional assemblies are typically very heavy and cumbersome, difficult to assemble and disassemble and do not readily permit rotation of the assembly, or any associated drill pipe or work string attached to said assembly. 
     Thus, there is a need for an pumping head assembly that can permit the pumping of fluids—including solids-laden fluids—into a well, especially at elevated pressures (such as during hydraulic fracturing and similar operations). 
     SUMMARY OF THE PRESENT INVENTION 
     The rotating high-pressure hydraulic fracturing head of the present invention utilizes a side entry method for receiving fluids from a manifold or other source. Such fluids are pumped into at least one side entry port of the rotating hydraulic fracturing head of the present invention. Thereafter, the fluids are directed into radially disposed flow holes on an internal mandrel, then directed down hole through the central bore of the mandrel and, eventually, into the well bore. 
     The pumping assembly of the present invention can be beneficially built/erected prior to being shipped to a well location. On its upper extent, the pumping assembly of the present invention will include a handling/landing pup joint, lift sub or other assembly handling device accepted by the top drive system—in most cases, said upper end of the present invention will have a threaded box-end connection. In the preferred embodiment, a portion of the invention situated between the box connection and inner radius mandrel has a closed bore/ID preventing upward flow to the top drive system. In the preferred embodiment, a double barrier well control system comprises double-stacked safety valves, or other double barrier system. 
     The present invention allows a user to pull stands or trip pipe while increasing safety and reducing wasted rig time by having eliminating the need for heavy, cumbersome lines to be removed, reinstalled and tested when rotation is required, such as when breaking out strands. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing summary, as well as the following detailed description of the preferred embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, the drawings show certain preferred embodiments. It is understood, however, that the invention is not limited to the specific methods and devices disclosed. 
         FIG. 1  depicts a side view of the rotating high-pressure pumping head of the present invention. 
         FIG. 2  depicts a hardened rotating tool housing to withstand/reduce washout. 
         FIG. 3  depicts a mandrel that can be inserted into the rotating tool housing depicted in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION 
       FIG. 1  depicts a side view of the rotating high-pressure pumping head of the present invention. Upper mandrel sub  1  has a box-end threaded connection, and an internal diameter that is not fully bored, thus preventing fluid leakage upward to the rotary shoulder box connection. 
     Plate  2 , beneficially including shackles  11 , pad eyes or other connection means, is affixed to the assembly, and can be connected by various methods to bails or other fixed structure of a top drive system, or snubbed off to a tugger line or rig structure, thereby preventing rotation of an outer swivel housing of the present invention while an inner mandrel and work string rotate. 
     In the preferred embodiment, inlet supply line  3  is bolted into the outer sleeve housing that can accommodate high pressure fluid flow. A plurality of bolt-on flanges can be provided, as well as a WECO connection 
     At least one ball drop sub  4  is provided to push trip activation balls into the work string and, ultimately, to permit such balls to flow down hole. Such ball drop subs can be manually or remote control actuated. In the preferred embodiment, a pin system is screwed inward toward the main bore ID where the ball inters the well bore; the pin beneficially includes a standoff that prevents the plug from hanging up if the pin is not retracted. 
     Main rotation unit  5  permits rotation of the work string and specialty tools (typically by way of a rig top drive system) while under pressure and flowing high pressure fluids. In the preferred embodiment, main rotation unit  5  comprises a side entry (double stacked) rotation tool (swivel) that has a continuous mandrel, not a two piece swivel. An outer housing allows pumping while simultaneous rotation and reciprocation can occur. It is to be observed that said main rotation unit can comprise separate but attached units, or a single machined part that appears as multiple units. 
     Bottom safety valve(s)  6  provides well control. In the preferred embodiment, said bottom safety valves include contingency remote control with manual override; such valves can be operated manually, or by way of remote control by air, fluid or signal to an actuating devise. 
     Outer sleeve  7  provides strength to an inserted mini-sub. Outer sleeve  7  can be slipped on, or an integral part of the pumping assembly of the present invention. Flow control (actuation) lines  8  are used when the remote system utilizes a fluid or air actuation device(s). 
     Lower swivel unit  9  is provided to control lower actuator unit(s). Lower swivel unit  9  is beneficially affixed to rotating tool housing unit and inner mandrel, thereby allowing air or fluid to flow to actuation devices. 
     Fluid/air feed and/or return lines  10  are provided when the remote system does not use a radio or other wireless signal to activate the actuation device(s). 
       FIG. 2  depicts a hardened rotating tool housing  12  to withstand/reduce washout. 
       FIG. 3  depicts mandrel  15  that is inserted into the rotating tool housing depicted in  FIG. 2 . In the preferred embodiment, mandrel  15  comprises radial flow apertures  14  and strike plates  13 . 
     The above-described invention has a number of particular features that should preferably be employed in combination, although each is useful separately without departure from the scope of the invention. While the preferred embodiment of the present invention is shown and described herein, it will be understood that the invention may be embodied otherwise than herein specifically illustrated or described, and that certain changes in form and arrangement of parts and the specific manner of practicing the invention may be made within the underlying idea or principles of the invention.