Cross-Reference to Related Applications

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 62/878,051, titled“MUD SHEARING UNIT, SYSTEM AND METHOD,” filed July 24, 2019, the entire disclosure of which is hereby incorporated herein by reference.

Background of the Disclosure

[0002] Hydrocarbon drilling systems utilize drilling fluid or mud (collectively referred to herein as“mud”) for drilling a wellbore in a subterranean formation. For example, mud may be pumped through a passage in a drill string to a drill bit connected to a lower end of the drill string. The mud is ejected from the drill string through ports in the drill bit, such as to cool the drill bit and transport materials cut from the wellbore to the surface via an annulus between the drill string and the sidewall of the wellbore. Upon reaching the surface, the mud is treated and stored prior to being pumped back into the drill string. Such treatments may include cuttings removal ( e.g ., using one or more shale shakers), degasifying, and/or other treatments.

[0003] Preparing mud for use, whether oil-based mud (OBM) or water-based mud (WBM), includes the addition of various chemicals that are mixed with the base mud component. In OBM applications, additives such as emulsifiers, organic clay, and coating agents may be added using a single shearing tank. The volume of the tank may impose a sheared volume limit, which may be less than the volume of mud to be used during some operations.

Summary of the Disclosure

[0004] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify

indispensable features of the claimed subject matter, nor is it intended for use as an aid in limiting the scope of the claimed subject matter.

[0005] The present disclosure introduces an apparatus that includes a mud shearing unit. The mud shearing unit includes an inlet, an outlet, a diffusion chamber in fluid connection with the outlet, a shearing nozzle in fluid connection between the inlet and the diffusion chamber, and a static fan disposed in the diffusion chamber at a position interrupting a flow path of mud flowing from the shearing nozzle to the outlet. The apparatus may further include a high-pressure mud pump and at least one tank. The high-pressure mud pump pumps mud to the inlet of the mud shearing unit at a first pressure. The at least one tank is in fluid communication with the outlet of the mud shearing unit, thereby receiving mud from the mud shearing unit at a second pressure that is less than the first pressure. The mud shearing unit may be configured to provide a predetermined pressure drop range between the first and second pressures. The at least one tank may be multiple tanks, and the apparatus may further include a low-pressure manifold in fluid connection between the outlet of the mud shearing unit and each of the tanks.

[0006] The present disclosure also introduces a method that includes adding drilling mud to each of a number of a set of tanks of a mud shearing system. The method also includes operating the mud shearing system to continuously shear the mud and distribute the sheared mud back to the number of the set of tanks via low-pressure equipment. The number of the set of tanks utilized for shearing is dependent upon a volume of a total amount of the mud to be sheared by the mud shearing system.

[0007] These and additional aspects of the present disclosure are set forth in the description that follows, and/or may be learned by a person having ordinary skill in the art by reading the material herein and/or practicing the principles described herein. At least some aspects of the present disclosure may be achieved via means recited in the attached claims.

Brief Description of the Drawings

[0008] The present disclosure is understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0009] FIG. l is a schematic view of at least a portion of a known mud shearing system.

[0010] FIG. 2 is a schematic view of at least a portion of an example implementation of a mud shearing system according to one or more aspects introduced in the present disclosure.

[0011] FIG. 3 is a schematic view of at least a portion of an example implementation of a mud shearing unit according to one or more aspects introduced in the present disclosure.

[0012] FIG. 4 is a sectional view of a portion of the mud shearing unit shown in FIG. 3.

[0013] FIG. 5 is another sectional view of another portion of the mud shearing unit shown in

FIG. 3.

[0014] FIG. 6 is a perspective view of a portion of the mud shearing unit shown in FIG. 3 [0015] FIG. 7 is another sectional view of another portion of the mud shearing unit shown in FIG. 3.

Detailed Description

[0016] It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments.

Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Moreover, the connection of a first feature to a second feature in the description that follows may include embodiments in which the first and second features are connected directly or connected indirectly by one or more additional features interposing the first and second features.

[0017] FIG. 1 is a schematic view of a conventional mud shearing system 100 utilized for a drilling process using OBM. Shearing of OBM additives, such as emulsifiers, organic clay, and coating agents, is performed in a single tank 110 designated for pre-mixing the additives into the OBM. The single tank 110 limits the sheared volume of pre-mixed OBM to the volume of the tank 110. A charge pump 120 pumps mud from the tank 110 (via a low-pressure (LP) suction line 130) to a high-pressure (HP) mud pump 140 (via a charge line 150). The mud pressurized by the HP mud pump 140 is routed back to the tank 110 (via an HP line 160) where a single shearing nozzle 170 shears the mud reentering the tank 110. The shearing nozzle 170 directs the sheared mud into a diffusor 180 so that the pressure drop does not damage components (not shown) within the tank 110. If the operation utilizing the OBM calls for a volume of OBM that is greater than the volume of the tank 110, OBM from other tanks 190 is similarly pre-mixed via similar operation of the pumps 120, 140 (or additional pumps, not shown), additional LP lines 195, and additional HP lines (not shown). However, such multi -tank implementations of the shearing system 100 are expensive and unreliable, such as due to the increased number of HP components ( e.g ., pumps, valves, pipes, fittings, etc.).

[0018] FIG. 2 is a schematic view of at least a portion of an example implementation of a mud shearing system 200 according to one or more aspects introduced in the present disclosure. The mud shearing system 200 depicted in FIG. 2, among other implementations within the scope of the present disclosure, is operable to continuously shear and distribute mud (OBM or WBM) through an LP manifold 210 to one or more tanks 220. The tanks 220 have a collective volume that meets or exceeds the volume of mud called for by an intended operation.

[0019] The mud shearing system 200 comprises a mud shearing unit 230 that receives HP mud (via an HP line 240) from an HP mud pump 250. A nozzle of the mud shearing unit 230 (described below) instantly shears the mud while the mud pressure decreases over the nozzle exit area ( e.g ., a diffusor, described below). Mud pressure is further decreased as the LP sheared mud flows through an LP sheared mud line 260 to the LP sheared mud manifold 210, flows within the LP sheared mud manifold 210, and flows through one or more LP sheared mud lines 270 into the larger area(s)/volume(s) of the active one(s) of the tanks 220. A charge pump 280 pumps mud from the active one or more tanks 220 (via one or more LP suction lines 285 from the corresponding tanks 220) to the HP mud pump 250 (via a charge line 290). A second LP manifold 215 may interpose the tanks 220 and the suction inlet of the charge pump 280, although other implementations may exclude the additional LP manifold 215 such that the LP suction lines 285 connect the tanks 220 and the charge pump 280.

[0020] The mud discharged from an exit 205 of the mud shearing system 200 (e.g., via LP sheared mud discharge lines 225 leading away from the corresponding active tanks 220 and/or an associated manifold 227) is at a low pressure. For example, the discharged mud may be at atmospheric pressure, or perhaps not more than about 25 psi (pounds per square inch) above atmospheric pressure. Accordingly, the piping, valves, and fittings of the mud shearing system 200 (except for the HP pump 250 and its fittings (not shown), the HP line 240, and HP components of the shearing unit 230 described below) may be for LP operations, perhaps in a manner permitting a reduction in manufacturing and maintenance costs relative to conventional mud shearing systems (such as the system 100 depicted in FIG. 1).

[0021] The mud shearing system 200 may be configured for use with OBM, WBM, or both. In implementations where both OBM and WBM can be used, one or more splitter boxes (not shown) can be provided along the mud return line 260 and/or other lines of the system 200.

[0022] FIG. 3 is a schematic view of at least a portion of an example implementation of the mud shearing unit 230 shown in FIG. 2, designated in FIG. 3 by reference number 300, according to one or more aspects introduced by the present disclosure. FIG. 4 is a sectional view of a portion of the mud shearing unit 300 shown in FIG. 3. The following description refers to FIGS. 3 and 4, collectively, and occasionally FIG. 2 where applicable. [0023] The mud shearing unit 300 receives HP mud ( e.g ., from the HP line 240 shown in FIG. 2) via an HP mud entry/inlet (e.g., a flange and/or other fitting) 305 through an HP mud shearing nozzle 310. The nozzle 310 may be easily accessible and interchangeable. For example, the entry 305 may be or comprise an American Petroleum Institute (API) flange to which the upstream end of the nozzle 310 is welded, threadedly-engaged, and/or otherwise connected, and the downstream end of the nozzle 310 may be threadedly engaged to the upstream end of a diffusion chamber 315 of the mud shearing unit 300. The nozzle 310 instantly shears the mud while the mud pressure decreases over the exit area of the nozzle 310 in the diffusion chamber 315.

[0024] As depicted in the example implementation shown in FIG. 3, the mud shearing unit 300 may also comprise a pressure safety valve 320, a diffusion chamber cover 325, and support legs 330. The pressure safety valve 320 may be operable in preventing over-pressurization in the diffusion chamber 315 (and/or the LP manifold 210), such as to release fluid from the diffusion chamber 315 when the internal pressure exceeds a pressure rating (or a predetermined percentage thereof) of the tank and components forming the diffusion chamber 315 and/or various components disposed in the diffusion chamber 315. The cover 325 may permit access to the interior of the diffusion chamber 315, such as to install or replace one or more static fans 335 disposed in the diffusion chamber 315 to interrupt a flow path of mud flowing from the nozzle 310 to an LP outlet 340 of the diffusion chamber 315. For example, the cover 325 may comprise a flange 345 connectable (e.g, via threaded fasteners 350) to a corresponding flange 355 of the diffusion chamber 315. The support legs 330 may support the mud shearing unit 300 at a height 360 (e.g, above ground, a wellsite surface, or another surface 365) that may ease access by a human operator.

[0025] In the example implementation depicted in FIG. 4, the mud shearing unit 300 comprises two static fans 335. However, other implementations within the scope of the present disclosure may comprise just one or more than two static fans 335. FIG. 5 is a sectional view of the mud shearing unit 300 along the section indicators in FIG. 4. FIG. 6 is a perspective view of an example implementation of at least one of the static fans 335 shown in FIGS. 4 and 5 according to one or more aspects introduced by the present disclosure. The following description refers to FIGS. 3-6, collectively.

[0026] FIG. 4 includes dashed lines indicating a flow path 370 of the mud flowing from the shearing nozzle 310 to the outlet 340. The dashed lines of the flow path 370 may (or may not, for some implementations) indicate a general or primary direction of mud flow relative to the interior surfaces of the diffusion chamber 315 that are visible in FIG. 4. For example, the mud flowing from the shearing nozzle 310 to the first-encountered static fan 335 ( i.e ., the static fan 335 that is closest to the shearing nozzle 310 relative to the other static fans 335) may generally be axial flow in the direction of ( e.g ., parallel to) a central, longitudinal axis 317 of the diffusion chamber 315, whereas the mud flowing between the static fans 335 may generally be helical in a clockwise direction, and the mud flowing away from the last-encountered static fan 335 (i.e., the static fan 335 that is closest to the outlet 340 relative to the other static fans 335) may generally be helical in a counter-clockwise direction until affected by the interior surface of the cover 325 and/or entering the conduit 342 comprising the outlet 340. However, such flow path 370 is merely an example, and is not limiting to the various implementations within the scope of the present disclosure, particularly implementations utilizing more than two static fans 335.

[0027] Nonetheless, each static fan 335 is disposed in the diffusion chamber 315 at positions interrupting the mud flow path 370 between the shearing nozzle 310 and the outlet 340. Each static fan 335 may be mounted on or otherwise coupled to a central member 375, such as may extend into contact with the interior surface of the cover 325, among other possible arrangements for fixing the longitudinal positions of the static fans 335 relative to the axis 317 of the diffusion chamber 315. The upstream end 377 of the central member 375 may be conical (as depicted), rounded, or otherwise shaped to direct a central-most (radially inward) portion of the mud flow toward blades 380 of the first-encountered static fan 335. Azimuthal/rotational positions of each static fan 335 may be maintained via engagement or other interaction between one or more notches or other recesses 385 of each static fan 335 with one or more rails 390 extending longitudinally along the interior surface of the diffusion chamber 315. Each rail 390 may be a discrete member welded or otherwise affixed to the interior surface of the diffusion chamber 315, as depicted in FIG. 5.

[0028] As most clearly depicted in FIGS. 5 and 6, each static fan 335 may comprise a plurality of blades 380 extending helically from a central opening (which receives the central member 375) toward an annular ring member 395. The one or more recesses 385 of each static fan 335 may extend radially into (or through) just the annular ring member 395, as shown in FIG. 5, or further radially into one or more of the blades 380.

[0029] FIG. 7 is a sectional view of at least a portion of an example implementation of the inlet 305 and the shearing nozzle 310. As described above, the inlet 305 may be or comprise an industry standard or other type of flange 400. The shearing nozzle 310 may be or comprise a standard, off-the-shelf, drill bit nozzle 405, such as may be found assembled in conventional subterranean well drill bits. However, other implementations of the shearing nozzle 310 within the scope of the present disclosure may comprise other types of nozzles 405. An adapter 410 may connect the nozzle 405 to the flange 400, such as via welding, threaded engagement, and/or other means. At least a portion 415 of an internal passage 420 of the adapter 410 may be generally conical or otherwise configured to reduce in cross-sectional area along the axial direction between the larger inner diameter 425 of the flange 400 to the smaller inner diameter 430 of a throat 435 the nozzle 405. The downstream end of the shearing nozzle 310 may include threads 440 and/or another interface for assembling the shearing nozzle 310 to the input end of the diffusion chamber 315.

[0030] The blades 380 of each static fan 335 are disposed at a non-zero angle relative to a primary direction of the portion of the flow path 370 that is between the shearing nozzle 310 and the first-encountered static fan 335, thereby forcing the mud flow impinging on the blades 380 to change direction within the diffusion chamber 315. For example, as shown in FIG. 6, the leading edge 381 of each blade 380 is about 90 degrees from the mud flow direction 370, and the trailing edge 382 of each blade 380 is about 70-80 degrees from the mud flow direction 370. In implementations utilizing two or more of the static fans 335, the non-zero angle at which the blades 380 of one of the static fans 335 are each disposed may be the same as or different from the non-zero angle at which the blades 380 of another one (or more) of the static fans 335 are each disposed. Such difference may be with respect to magnitude. For example, the blades 380 of one of the static fans 335 may generally be of the form of a quadruple helix having a first pitch, and the blades 380 of another one (or more) of the static fans 335 may generally be of the form of a quadruple helix having a second pitch that is greater than or less than the first pitch.

The difference between the non-zero blade angles of different ones of the static fans 335 may also (or instead) be with respect to polarity/direction. For example, the blades 380 of one of the static fans 335 may generally be of the form of a right-handed quadruple helix, and the blades 380 of another one (or more) of the static fans 335 may generally be of the form of a left-handed quadruple helix.

[0031] The shearing nozzle 310 and the one or more static fans 335 collectively induce a predetermined reduction of a first mud pressure at the inlet 305 to a second mud pressure at the outlet 340. The predetermined reduction may be based on the number of static fans 335 comprised by the mud shearing unit 300, the non-zero angle of each blade 380 of each static fan 335, and/or a surface area of each blade 380 of each static fan 335. For example, the mud pressure at the inlet 305 may be about 100 psi and the mud pressure at the outlet 340 may be within about 25 psi of atmospheric pressure at the wellsite. As schematically depicted in FIGS. 3 and 4, the mud shearing unit 300 may also comprise a number of sensors 302 for monitoring pressure, temperature, and/or fluid level at positions proximate the inlet 305, the upstream end of the diffusion chamber 315, the outlet 340, and/or one or more intermediate positions in the diffusion chamber 315 between the shearing nozzle 310 and the outlet 340, perhaps between each neighboring pair of static fans 335. However, it is to be understood that the actual types and placement of the sensors 302 will differ from their schematic depiction in FIGS. 3 and 4.

[0032] Although not shown in the figures, the mud shearing unit 300 may also comprise sound insulation means. For example, batting, baffling, and/or other means may substantially surround at least a portion of the diffusion chamber 315 to reduce the sound levels resulting from the rapid expansion of flow area from the shearing nozzle 310 into the diffusion chamber 315 and/or the turbulent mud flow caused by the static fans 335. Such sound insulation means may be removable.

[0033] It is also to be understood that, despite their omission from the figures (for the purposes of clarity and ease of understanding), a shearing system according to one or more aspects introduced by the present disclosure may comprise additional containers, flanges, fittings, conduits, electronic communication means, instrumentation, controllers, and/or other components.

[0034] In view of the entirety of the present disclosure, including the figures and the claims, a person having ordinary skill in the art will readily recognize that the present disclosure introduces an apparatus comprising a mud shearing unit that comprises: an inlet; an outlet; a diffusion chamber in fluid connection with the outlet; a shearing nozzle in fluid connection between the inlet and the diffusion chamber; and a static fan disposed in the diffusion chamber at a position interrupting a flow path of mud flowing from the shearing nozzle to the outlet.

[0035] The shearing nozzle and the static fan may collectively induce a predetermined reduction of a first mud pressure at the inlet to a second mud pressure at the outlet.

[0036] The shearing nozzle shears the mud flowing therethrough.

[0037] The static fan may comprise a plurality of blades each disposed at a non-zero angle relative to a primary direction of the flow path between the shearing nozzle and the static fan, thereby forcing the mud flow impinging on the blades to change direction within the diffusion chamber. The static fan may be a first static fan, the position at which the first static fan is disposed in the diffusion chamber may be a first position, and the mud shearing unit may further comprise a second static fan disposed in the diffusion chamber at a second position between the first static fan and the outlet. The plurality of blades may be a plurality of first blades, the non zero angle may be a first non-zero angle, and the second static fan may comprise a plurality of second blades each disposed at a second non-zero angle relative to the primary direction of the flow path between the shearing nozzle and the first static fan, thereby forcing the mud flow impinging on the second blades to further change direction within the diffusion chamber. The first and second non-zero angles may be different in magnitude. The first and second non-zero angles may collectively comprise a positive angle and a negative angle.

[0038] The static fan may comprise a plurality of blades each disposed at a non-zero angle relative to a central, longitudinal axis of the diffusion chamber, the shearing nozzle and the static fan may collectively induce a predetermined reduction of a first mud pressure at the inlet to a second mud pressure at the outlet, and the predetermined reduction of the first mud pressure may be based on the non-zero angle of each blade of the static fan and a surface area of each blade of the static fan.

[0039] The static fan may be one of a plurality of static fans comprised by the mud shearing unit and disposed between the shearing nozzle and the outlet, each of the plurality of static fans may comprise a plurality of blades each disposed at a non-zero angle relative to a longitudinal axis of the diffusion chamber, the shearing nozzle and the plurality of static fans may collectively induce a predetermined reduction of a first mud pressure at the inlet to a second mud pressure at the outlet, and the predetermined reduction of the first mud pressure may be based on: the number of the plurality of static fans comprised by the mud shearing unit; the non-zero angle of each blade of each of the plurality of static fans; and a surface area of each blade of each of the plurality of static fans.

[0040] The apparatus may further comprise: a high-pressure mud pump operable to pump mud to the inlet of the mud shearing unit at a first pressure; and at least one tank in fluid communication with the outlet of the mud shearing unit, thereby receiving mud from the mud shearing unit at a second pressure that is less than the first pressure. The mud shearing unit may be configured to provide a predetermined pressure drop range between the first and second pressures. [0041] The at least one tank may be a plurality of tanks, and the apparatus may further comprise a low-pressure manifold in fluid connection between the outlet of the mud shearing unit and each of the plurality of tanks.

[0042] The at least one tank may be a plurality of tanks, and the apparatus may further comprise a low-pressure manifold in fluid connection between the high-pressure pump and each of the plurality of tanks. The apparatus may further comprise a charge pump operable to pump mud from the low-pressure manifold to the high-pressure pump.

[0043] The apparatus may further comprise a charge pump operable to pump mud from the at least one tank to the high-pressure pump.

[0044] The present disclosure also introduces a method comprising adding drilling mud to each of a number of a plurality of tanks of a mud shearing system and operating the mud shearing system to: continuously shear the mud; and distribute the sheared mud back to the number of the plurality of tanks via low-pressure equipment; wherein the number of the plurality of tanks is dependent upon a volume of a total amount of the mud to be sheared by the mud shearing system.

[0045] The method may further comprise adding a mud additive to one or more of the number of the plurality of tanks such that the mud additive mixes with the mud while the mud shearing system is operated to continuously shear the mud.

[0046] The mud shearing system may comprise a mud shearing unit comprising an inlet, an outlet, a shearing nozzle, and at least one static fan. The shearing nozzle and the at least one static fan may collectively induce a predetermined reduction of a first mud pressure at the inlet to a second mud pressure at the outlet.

[0047] The mud shearing system may comprise a mud shearing unit comprising an inlet, an outlet, a shearing nozzle, a plurality of static fans, and a diffusion chamber comprising the plurality of static fans. Each of the plurality of static fans may comprise a plurality of blades each disposed at a non-zero angle relative to a central, longitudinal axis of the diffusion chamber. The shearing nozzle and the plurality of static fans may collectively induce a predetermined reduction of a first mud pressure at the inlet to a second mud pressure at the outlet. The predetermined reduction of the first mud pressure may be based on the number of the plurality of static fans comprised by the mud shearing unit, the non-zero angle of each blade of each of the plurality of static fans, and a surface area of each blade of each of the plurality of static fans. [0048] The low-pressure equipment may comprise a low-pressure manifold that: receives the sheared mud from a mud shearing unit of the mud shearing system; and distributes the sheared mud to each of the number of the plurality of tanks.

[0049] The foregoing outlines features of several embodiments so that a person having ordinary skill in the art may better understand the aspects of the present disclosure. A person having ordinary skill in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same functions and/or achieving the same benefits of the embodiments introduced herein. A person having ordinary skill in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

[0050] The Abstract at the end of this disclosure is provided to comply with applicable rules and regulations and to permit the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.