Modular Downhole Junk Basket Assembly
A modular junk basket assembly adapted for attachment to a wellbore tubing string comprises a tubular body having a plurality of debris ports that feed into an integrally formed basket space. A baffle is slidably mounted on the tubular body which translates along the length of the tubular body to a position behind the debris ports, relative to the fluid pressure created on the baffle. The baffle has a plurality of fluid passageways which allow passage of drilling fluid and small debris as larger debris is diverted toward the debris ports and into the debris basket.
This application claims priority to U.S. provisional application Ser. No. 62/094,776 filed Dec. 12, 2014 entitled “Modular Downhole Junk Basket Assembly”, the entire content of which is incorporated by reference.
FIELD OF THE INVENTIONThis invention relates to an oilfield tool and more particularly to a modular downhole collection basket with an articulable baffle to deflect debris into a debris basket opening.
BACKGROUND OF THE INVENTIONVarious types of debris or junk basket assemblies have been devised for collecting drilling fluid debris such as mud cake, cement and cement cake, and metal and plastic fragments from a wellbore during a cleaning operation. The conventional junk basket assembly has a debris basket dimensioned to collect debris flowing around and external to the debris basket. The top end of the debris basket is open and relies on free falling debris in the upward flowing drilling fluid to fall into the opening of the debris basket where it remains until the debris basket is removed. However, the force of the upward-flowing drilling fluid carrying the debris can divert a substantial portion of the debris away from the basket impeding the collection of the drilling fluid debris in the debris basket. This is problem particularly occurs when fluid circulates through the debris basket and upward through an annulus in the well as the basket is retrieved to the surface. Other debris baskets have complicated designs with multiple components making them expensive to build.
During this circulation of fluid F in wellbore 7, fluid F has a first velocity as it circulates through wellbore flow area A in annular space 8. When Fluid F flows upward in the annular space 8 through wellbore flow area B at debris basket 4, fluid F has a second velocity that is greater than the first velocity in wellbore flow area A because flow area A of annular space 8 is decreased between the casing 3 and the debris basket 4. As fluid F continues to flow upward in wellbore 7 toward the surface, annular space 8 abruptly widens directly above the debris basket 4. This widening of annular space 8 creates an increased flow area C in annular space 8 so that the velocity of fluid F in flow area C decreases to a third velocity that is less than the second fluid velocity created in flow area B.
The decrease in fluid velocity from flow area B to flow area C creates eddy currents that divert a portion of the fluid F entering flow area C from flow area B toward central mandrel 2 above the opening 4a of debris basket 4 into flow area E of annular space 8. The fluid diverted into flow area d se c into flow area E and into opening 4a of debris basket 4 so that debris carried by that portion of fluid F is captured and collected in debris basket 4. However, simultaneously, a portion of the fluid F entering flow area C from flow area B will flow upward in annular space 8 into flow area D and will remain uncaptured as the fluid F flow upward to the wellbore surface. Thus, at least some of the flow of fluid F in annular space 8 is diverted away from the debris basket 4 of conventional a junk basket assembly and the collection of debris in fluid F by debris basket 4 is impeded.
From the foregoing it can be seen that there is a continuing need for a junk basket assembly that will reduce fluid diversion away from the debris basket as fluid flows toward the surface of the wellbore and that will increase the rate of wellbore debris collection during cleaning operations.
SUMMARY OF THE INVENTIONThe present invention provides a tubular modular junk basket assembly adapted for attachment to a tubing string used in a wellbore for collection of drilling fluid debris to satisfy the aforementioned needs. The modular junk basket assembly has a central tubular mandrel or tool body, an integrated debris collection basket operable to collect debris from the wellbore drilling fluid, and a slidably translatable baffle operable to deflect and divert fluid and debris flowing in the wellbore annulus around the debris basket assembly into the debris collection basket. The integrated debris collection basket has a plurality of debris ports distributed radially about the peripheral radial surface of the tubular tool body. The slidably translatable baffle has a plurality of fluid passages to allowing fluid flow through the baffle as the junk basket assembly is moved into and out of a wellbore. Fluid pressure against the translatable baffle created as fluid flows around the junk basket assembly slides the baffle along the tool body to a desired position adjacent the debris ports in the direction of fluid flow to deflect and divert debris of a desired size through the debris ports and into the debris collection basket while allowing fluid and debris of a lessor size to pass through the baffle fluid passages and circulate in the wellbore.
Tool body 100 of junk basket assembly 10 has an upper end connection 20 configured for threadable attachment to an upper tubing string 15, a lower end connection 26 configured for threadable attachment to a lower tubing string 17, and a central through-bore 22 in communication with the through-bore in the upper tubing string 15 and the lower tubing string 17. The upper tubing string 15 and lower tubing string 17 with the attached basket assembly 10 are positioned in a wellbore 12 having an interior surface 14 such as the interior surface of a casing string 16.
The casing string 16 may be in fluid communication with a hydrocarbon formation. The modular junk basket assembly 10 may be of any suitable diameter to fit within the interior surfaces 14 of casing string 16 while creating an annular space 42 in the wellbore 12 between the casing string 16 and the tool assembly 10 and the upper and lower tubing strings 15 and 17 through which debris and drilling fluid F may pass.
The assembly 10 is comprised of a longitudinally extending tubular mandrel creating tubular tool body 100. Tubular tool body 100 has an integrally formed longitudinally extending debris collection basket 40 with an upper basket end 41 and a lower basket end 43. Debris collection basket 40 has a cover 19 with a plurality of debris ports 18 distributed radially about the cover 19 in proximity to the upper basket end 41 and a plurality of fluid drain holes 45 distributed radially about the cover 19 in proximity to the basket lower end 43. The debris ports 18 and drain holes 45 provide fluid communication between debris collection basket 40 and the annular space 42. The drain holes 45 provide a means for draining drilling fluid and small debris from the collection basket 40 as debris laden fluid is delivered into the basket 40 through debris ports 18.
A translatable ring-shaped baffle 50 is slidably mounted around the tool body 100 so that the ring-shaped baffle 50 is slidably translatable longitudinally along the tool body 100 across the debris ports 18 of the basket 40 between a first radial shoulder 56a constructed around the tool body 100 adjacent to the upper end of the collection ports 18 and an opposing second radial shoulder 56b constructed around the tool body 100 adjacent to the lower end of the collection ports 18 as shown in
Cover 19 of the debris collection basket 40 may be fabricated as a separate tubular and welded or otherwise attached to the tool body 100 or it may be integrally formed as part of the tool body 100. Because tool body 100 holds the weight of the lower tubing string 17 and transfers the torque from the upper tubing string 15 to the lower tubing string 17, it must be sized and constructed of material having sufficient strength to withstand the tensile and torsional forces being created. Preferably the tool body 100 and cover 19 are constructed and arranged as a single unitary structure to eliminate multiple parts which are subject to failure during operation. In one configuration, only the tool body 100 is made of high strength steel. The baffle 50 may be manufactured from steel or other material having a lessor yield strength as it need only to withstand forces created from drilling fluid pressure and wellbore debris and obstructions and not the torque and weight imposed by the upper and lower tubing strings.
A plurality of centralizers 46 are positioned about tool body 100 to keep the assembly 10 centralized within the casing string 16. When installed between the upper tubing string 15 and the lower tubing string 17 and inserted into wellbore 12, junk basket assembly 10 substantially tracks the inner surface 14 of casing string 16. The centralizers 46 are configured to slidably abut the interior surface 14 of casing string 16 to maintain the centralized position of assembly 10 and minimize the risk of frictional or collision damage to the baffle 50 and the tool body 100 caused by contact with the casing string 16. The baffle 50 is configured to have a diameter less than the drift diameter of the tool body and centralizers 46.
Now referring to
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As shown in
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Each high-flow baffle 150 is slidably mounted around tool body 100 to slidably translate longitudinally along said tool body 100 on a plurality of linear slides 31. The linear slides 31 may be grooves or slots 32 that correspond with longitudinally extending slide rails 33 spaced radially around the outer peripheral surface of the tool body 100 as shown in
When assembled as shown in
When junk basket assembly 10A is in use in high-flow conditions, the staggered high-flow baffles 150 will divert debris carried by the wellbore fluid F into the collection basket 40 of the assembly 10A. If basket 40 fills with debris, such that uncollected debris will clog the flow space provided by annular space 42 and the flow slots 52 of the high-flow baffles 150, and the force generated by fluid F against the clogged baffles 150 reaches a predetermined force, the screws 30 releasably holding the upper high-flow baffle 150 in place against retaining ring 53 adjacent the lower high-flow baffle 150 will shear or sever. The severed shear screws 30 releases the upper high-flow baffle 150 allowing it to slidably translate longitudinally on slides 131 along tool body 100 and separate from lower high-flow baffle 150 which will be restrained from translation by retaining structure 35.
The separation of upper and lower high-flow baffles 150 opens flow spaces 154 and creates a flow path 155 for fluid F through the flow gaps 153 of the upper and lower high-flow baffles 150 as shown in
When one of the high-flow baffles 150 becomes clogged and the fluid pressure on the clogged high-flow baffle 150 increases above the compression force exerted by corresponding springs 58a or 58b so that the clogged baffle 150 is no longer restrained and held in position against retaining structure 35 by the compression springs 58a or 58b, the clogged high-flow baffle 150, whether upper or lower high-flow baffle 150, will separate and slide along liner slides 31 to open the flow spaces 154 across the flow gaps 153 of the upper and lower high-flow baffles 150 to create flow path 155 for fluid F between the upper and lower high-flow baffles 150 in the manner shown in
Each spring 58a and 58b may be positioned around a guide rod 59 that extends longitudinally along the body 100. The guide rods 59 may also serve as the linear slides 31 used for orientation of the upper and lower baffles 150.
Changes may be made in the form, construction and arrangement of the parts of the junk basket assembly described herein without departing from the spirit and scope of the invention or sacrificing any of the invention's material advantages. The description and drawings provide only exemplary embodiments and the invention can be practiced by other than the described embodiments, which are presented only for illustration and not limitation.
Claims
1. A modular junk basket assembly comprising:
- (a) a longitudinally extending tubular tool body having a central through-bore, an upper end, and a lower end;
- (b) a debris basket within said tool body;
- (c) a plurality of radially distributed debris ports in communication with said debris basket; and
- (d) a ring-shaped baffle slidably mounted around said longitudinally extending tool body, said baffle slidably translatable along said longitudinally extending tool body across said plurality of debris ports.
2. The modular junk basket assembly recited in claim 1, wherein said debris ports are positioned between a first shoulder positioned at the periphery of said tool body and a second shoulder positioned at the periphery of said tool body whereby said baffle is slidably translatable between said first and second shoulders.
3. The modular junk basket assembly recited in claim 2, wherein said baffle has a plurality of flow slots.
4. The modular junk basket assembly recited in claim 3, wherein said flow slots are radially spaced around the periphery of said baffle.
5. The modular junk basket assembly recited in claim 3, wherein said flow slots are holes through said baffle.
6. The modular junk basket assembly recited in claim 4, wherein said flow slots are U-shaped.
7. The modular junk basket assembly recited in claim 3, wherein said baffle has an inwardly angled wall.
8. A modular junk basket assembly comprising:
- (a) a longitudinally extending tubular tool body having a central through-bore, an upper end, and a lower end;
- (b) a debris basket within said tool body;
- (c) a plurality of radially distributed debris ports in communication with said debris basket;
- (d) a first shoulder on the periphery of said tool body;
- (e) a second shoulder on the periphery of said tool body;
- (f) a retaining structure at the periphery of said tool body positioned between said first shoulder and said second shoulder; and
- (g) a first ring-shaped baffle slidably mounted around said longitudinally extending tool body and a second ring-shaped baffle slidably mounted around said longitudinally extending tool body, said first and second baffles releasably restrained against said retaining structure.
9. The modular junk basket assembly recited in claim 8, wherein said first and second baffles have a plurality of equally spaced flow gaps along the radial periphery of said baffles, said flow gaps providing a plurality of fluid flow space across each of said first and second baffles.
10. The modular junk basket assembly recited in claim 9, wherein said first and said second ring-shaped baffles are oriented on said tool body to stagger said flow gaps and close said fluid flow space across each of said first and second baffles.
11. The modular junk basket assembly recited in claim 10, wherein said first and second baffles are slideably retained on linear slides.
12. The modular junk basket assembly recited in claim 11, wherein said first and second baffles are releasably restrained by shear screws or by shear pins.
13. The modular junk basket assembly recited in claim 11, wherein said first and second baffles are releasably restrained by compression springs.
14. A method of removing debris from fluid in a wellbore, comprising the steps of:
- (a) providing a junk basket assembly comprising: (i) a longitudinally extending tubular tool body having a central through-bore, an upper end, and a lower end; (ii) a debris basket within said tool body; (iii) a plurality of radially distributed debris ports in communication with said debris basket; and (iv) a ring-shaped baffle slidably mounted around said longitudinally extending tool body, said baffle slidably translatable along said longitudinally extending tool body across said plurality of debris ports;
- (b) attaching said junk basket assembly to a tubing string;
- (c) inserting said tubing string with said attached junk basket assembly into a wellbore thereby creating a annular space for wellbore fluid between said wellbore and said junk basket assembly; and
- (d) providing an upward flow of wellbore fluid in said annular space, said wellbore fluid carrying wellbore debris, whereby fluid pressure on said baffle slides said baffle to a position upward from said fluid ports thereby diverting at least some of said debris in said wellbore fluid through said plurality of debris ports and into said debris basket.
15. The method of claim 14, further comprising the step of providing a downward flow of wellbore fluid in said annular space, said wellbore fluid carrying wellbore debris, whereby fluid pressure on said baffle slides said baffle to a position downward from said fluid ports thereby diverting at least some of said debris in said wellbore fluid through said plurality of debris ports and into said debris basket.
16. The method as recited in claim 15 further comprising the step of providing said baffle with a plurality of flow slots, said flow slots allowing said wellbore fluid and a least some wellbore debris to flow through said slots.
17. A method of removing debris from fluid in a wellbore, comprising the steps of:
- (a) providing a junk basket assembly comprising: (i) a longitudinally extending tubular tool body having a central through-bore, an upper end, and a lower end; (ii) a debris basket located within said tool body; (iii) a plurality of radially distributed debris ports in communication with said debris basket; (iv) a first shoulder extending radially around the periphery of said tool body; (v) a second shoulder extending radially around the periphery of said tool body; (vi) a first releasably restrained ring-shaped baffle slidably mounted around said longitudinally extending tool body and a second releasably restrained ring-shaped baffle slidably mounted around said longitudinally extending tool body; and (vii) a retaining structure between said first shoulder and said second shoulder, said retaining structure sandwiched by said first and said second releasably restrained baffles;
- (b) attaching said junk basket assembly to a tubing string;
- (c) inserting said tubing string with said attached junk basket assembly into a wellbore thereby creating a annular space for wellbore fluid between said wellbore and said junk basket assembly;
- (d) providing an upward flow of wellbore fluid in said annular space, said wellbore fluid carrying wellbore debris, whereby at least a portion of said wellbore debris is diverted by said first and second baffles into said debris basket; and
- (e) wherein when fluid pressure of said upward flow of wellbore fluid on said first and second baffles reaches a predetermined pressure force, said releasably restrained first baffle is released to slidably translate away from said second baffle thereby creating a flow space between said first baffle and said second baffle.
18. The method of claim 17, further comprising the step of providing a downward flow of wellbore fluid in said annular space, said wellbore fluid carrying wellbore debris, said wellbore fluid carrying wellbore debris, whereby at least a portion of said wellbore debris is diverted by said first and second baffles into said debris basket, wherein when fluid pressure on said first and second baffles reaches a predetermined pressure force, said releasably restrained second baffle is released to slidably translate away from said first baffle thereby creating a flow space between said first baffle and said second baffle.
19. The method of claim 18 wherein said first ring-shaped baffle and said second ring-shaped baffle have a plurality of flow gaps.
20. The method as recited in claim 19 wherein said first ring-shaped baffle and said second ring-shaped baffle are oriented on said tool body whereby said flow gaps of said first and said second baffles are closed.
Type: Application
Filed: Dec 16, 2015
Publication Date: Jun 23, 2016
Inventors: Dennis Joel Penisson (Raceland, LA), Wilbert A. Dean (Houma, LA)
Application Number: 14/971,642