Patent ID: 12188327

DETAILED DESCRIPTION OF THE INVENTION

FIG.9shows generally an oil well drilling structure10that can provide a platform11such as a marine platform as shown. Such platforms11are well known. Platform11supports a derrick12that can be equipped with a lifting device21that supports a top drive unit13. Such a derrick12and top drive unit13are well known. A top drive unit13can be seen for example in U.S. Pat. Nos. 4,854,383 and 4,722,389 which are incorporated herein by reference.

A flow line14can be used for providing a selected fluid such as a fluidized cement or fluidized setable material to be pumped into the well during operations which are known in the industry and are sometimes referred to as cementing operations. Such cementing operations are discussed for example in prior U.S. Pat. Nos. 3,828,852; 4,427,065; 4,671,353; 4,782,894; 4,995,457; 5,236,035; 5,293,933; and 6,182,752, each of which is incorporated herein by reference. A tubular member22can be used to support plug dropping head15at a position below top drive unit13as shown inFIG.9. String16is attached to the lower end portion of plug dropping head15.

InFIG.9, the platform11can be any oil and gas well drilling platform11such as a marine platform shown in a body of water18that provides a seabed or mud line17and water surface19. Such a platform11provides a platform deck20that affords space for well personnel to operate and for the storage of equipment and supplies that are needed for the well drilling operation.

A well bore23extends below mud line17. InFIGS.10and11, the well bore23can be surrounded with a surface casing24. The surface casing24can be surrounded with cement/concrete25that is positioned in between a surrounding formation26and the surface casing24. Similarly, a liner or production casing32extends below surface casing24. The production casing32has a lower end portion that can be fitted with a casing shoe27and float valve28as shown inFIGS.10-16. Casing shoe27has passageway30. Float valve28has passageway29.

The present invention provides an improved method and apparatus for dropping balls, plugs, darts or the like as a part of a cementing operation. Such cementing operations are in general known and are employed for example when installing a liner such as liner32. In the drawings, arrows75indicate generally the flow path of fluid (e.g. cement, fluidized material or the like) through the tool body34. In that regard, the present invention provides an improved ball or plug or dart dropping head15that is shown inFIGS.1-8,10-17and18-33. InFIGS.1A,1B,1C and2-8, ball/plug dropping head15has an upper end portion31and a lower end portion33. Ball/plug dropping head15provides a tool body34that can be of multiple sections that are connected together, such as with threaded connections. In FIGS.1A-1C, the tool body34includes sections35,36,37,38,39. The section35is an upper section. The section39is a lower section.

Ball/plug dropping head15can be pre-loaded with a number of different items to be dropped as part of a cementing operation. For example, inFIGS.1A,1B,1Cthere are a number of items that are contained in ball/plug dropping head15. These include an upper, larger diameter ball dart40,41and smaller diameter ball42. InFIGS.18-26, an alternate embodiment is shown which enables very small diameter balls, sometimes referred to as “frac-balls”102(which can have a diameter of between about ½ and ⅝ inches) to be dispensed into the well below toll body34.

The tool body34supports a plurality of valving members at opposed openings90. The valving members can include first valving member43which is an upper valving member. The valving members can include a second valving member44which is in between the first valving member43and a lower or third valving member45. Valving member43attaches to tool body34at upper opening positions61,62. Valving member44attaches to tool body34at middle opening positions63,64. Valving member45attaches to tool body43at lower opening positions65,66.

Threaded connections46,47,48,49can be used for connecting the various body sections35,36,37,38,39together end to end as shown inFIGS.1A,1B,1C. Tool body34upper end31is provided with an internally threaded portion50for forming a connection with tubular member22that depends from top drive unit13as shown inFIG.9. A flow bore51extends between upper end31and lower end33of tool body34.

Sleeve sections52are secured to tool body34within bore15as shown inFIGS.1A,1B,1C. Sleeves52can be generally centered within bore51as shown inFIGS.1A,1B,1Cusing spacers67that extend along radial lines from the sections35-39.

Each valving member43,44,45is movable between open and closed positions. InFIGS.1A,1B,1Ceach of the valving members43,44,45is in a closed position. In that closed position, each valving member43,44,45prevents downward movement of a plug, ball40,42, or dart41as shown. InFIG.1A, the closed position of valving member43prevents downward movement of larger diameter ball40. Similarly, inFIG.1B, a closed position of valving member44prevents a downward movement of dart41. InFIG.1B, a closed position of valving member45prevents a downward movement of smaller diameter ball42. In each instance, the ball, dart or plug rests upon the outer curved surface68of valving member43,44or45as shown in the drawings.

Each valving member43,44,45provides a pair of opposed generally flat surfaces69,70(seeFIGS.3,6,17).FIG.17shows in more detail the connection that is formed between each of the valving members43,44,45and the tool body34. The tool body34provides opposed openings90that are receptive the generally cylindrically shaped valve stems54,55that are provided on the flat sections or flat surfaces69,70of each valving member43,44,45. For example, inFIGS.6and17, the flat surface69provides valve stem54. Openings90are receptive of the parts shown in exploded view inFIG.17that enable a connection to be formed between the valving member43,44or45and the tool body34. For the stem55, fastener91engages an internally threaded opening of stem55. Bushing92is positioned within opening90and the outer surface of stem55registers within the central bore95of bushing92. Bushing92is externally threaded at93for engaging a correspondingly internally threaded portion of tool body34at opening90. O-rings60can be used to interface between stem55and bushing92. A slightly different configuration is provided for attaching stem54to tool body34. Sleeve94occupies a position that surrounds stem54. Sleeve54fits inside of bore95of bushing92. The externally threaded portion93of bushing92engages correspondingly shaped threads of opening90. Pins99form a connection between the stem54at openings98and the sleeve94. Fastener96forms a connection between bushing92and an internally threaded opening97of stem54. As assembled, this configuration can be seen inFIG.1Afor example. The flat surfaces69,70enable fluid to flow in bore51in a position radially outwardly or externally of sleeve or sleeve section52by passing between the tool body sections35,36,37,38,39and sleeve52. Thus, bore51is divided into two flow channels. These two flow channels71,72include a central flow channel71within sleeves52that is generally cylindrically shaped and that aligns generally with the channel53of each valving member43,44,45. The second flow channel is an annular outer flow channel72that is positioned in between a sleeve52and the tool body sections35,36,37,38,39. The channels71,72can be concentric. The outer channel72is open when the valving members43,44,45are in the closed positions ofFIGS.1A,1B and1C, wherein central flow channel71is closed. When the valving members43,44,45are rotated to a closed position, fins73become transversely positioned with respect to the flow path of fluid flowing in channel72thus closing outer flow channel72(seeFIG.5). This occurs when a valving member43,44,45is opened for releasing a ball40or42or for releasing dart41.FIG.4illustrates a closed position (FIG.4) of the valving member45just before releasing smaller diameter ball42. Fins73are generally aligned with bore15and with flow channels71,72when flow in channel72is desired (FIG.4). InFIG.4, valving member45is closed and outer flow channel72is open.

InFIGS.2-3,5and7-8, a tool74has been used to rotate valving member45to an open position that aligns its channel53with central flow channel71enabling smaller diameter ball42to fall downwardly via central flow channel71(FIG.8). InFIG.5, outer flow channel72has been closed by fins73that have now rotated about 90 degrees from the open position ofFIG.4to the closed position. Fins73close channel72inFIG.5. It should be understood that tool74can also be used to rotate valving member44from an open position ofFIG.1Bto a closed position such as is shown inFIG.5when it is desired that dart41should drop. Similarly, tool74can be used to rotate upper valving member43from the closed position ofFIG.1Ato an open position such as is shown inFIG.5when it is desired to drop larger diameter ball40.

FIGS.7-16illustrate further the method and apparatus of the present invention. InFIG.8, lower or third valving member45has been opened as shown inFIG.5releasing smaller diameter ball42. InFIG.8, smaller diameter ball42is shown dropping wherein it is in phantom lines, its path indicated schematically by arrows75.

FIG.10shows a pair of commercially available, known plugs76,77. These plugs76,77include upper plug76and lower plug77. Each of the plugs76,77can be provided with a flow passage79,81respectively that enables fluid to circulate through it before ball42forms a seal upon the flow passage81. Smaller diameter ball42has seated upon the lower plug77inFIG.10so that it can now be pumped downwardly, pushing cement80ahead of it. InFIG.11, arrows78schematically illustrate the downward movement of lower plug77when urged downwardly by a pumped substance such as a pumpable cement or like material80. Each of the plugs76,77can be provided with a flow passage79,81respectively that enables fluid to circulate through it before ball42forms a seal upon the flow passage81(seeFIG.11). When plug77reaches float valve28, pressure can be increased to push ball42through plug77, float valve28and casing shoe27so that the cement flows (see arrows100,FIG.11) into the space101between formation26and casing32.

InFIG.12, second valving member44is opened releasing dart41. Dart41can be used to push the cement80downwardly in the direction of arrows82. A completion fluid or other fluid83can be used to pump dart41downwardly, pushing cement80ahead of it. Once valves44and45are opened, fluid83can flow through openings84provided in sleeves52below the opened valving member (seeFIG.7) as illustrated inFIGS.7and12. Thus, as each valving member43or44or45is opened, fluid moves through the openings84into central flow channel71.

When valve44is opened, dart41can be pumped downwardly to engage upper plug76, registering upon it and closing its flow passage79, pushing it downwardly as illustrated inFIGS.14and15. Upper plug79and dart41are pumped downwardly using fluid83as illustrated inFIGS.14and15. InFIG.16, first valving member43is opened so that larger diameter ball40can move downwardly, pushing any remaining cement80downwardly.

The ball40can be deformable, so that it can enter the smaller diameter section86at the lower end portion of tool body34. During this process, cement or like mixture80is forced downwardly through float collar28and casing shoe27into the space that is in between production casing32and formation26. This operation helps stabilize production casing32and prevents erosion of the surrounding formation26during drilling operations.

During drilling operations, a drill bit is lowered on a drill string using derrick12, wherein the drill bit simply drills through the production casing32as it expands the well downwardly in search of oil.

FIGS.18-26show an alternate embodiment of the apparatus of the present invention, designated generally by the numeral110inFIGS.22-23. InFIGS.18-26, the flow openings84in sleeves52of ball/plug dropping head110ofFIGS.1-17have been eliminated. Instead, sliding sleeves111are provided that move up or down responsive to movement of a selected valving member112,113. It should be understood that the same tool body34can be used with the embodiment ofFIGS.18-26, connected in the same manner shown inFIGS.1-17to tubular member22and string16. InFIGS.18-26, valving members112,113replace the valving members43,44,45ofFIGS.1-17. InFIGS.18-26, sleeves111replace sleeves52. While two valving members112,113are shown inFIGS.22,23, it should be understood that three such valving members (and a corresponding sleeve111) could be employed, each valving member112,113replacing a valving member43,44,45ofFIGS.1-17.

InFIGS.18-26, tool body34has upper and lower end portions31,33. As with the preferred embodiment ofFIGS.1-17, a flow bore51provides a central flow channel71and outer flow channel72. Each valving member112,113provides a valve opening114. Each valving member112,113provides a flat surface115(seeFIG.20). Each valving member112,113provides a pair of opposed curved surfaces116as shown inFIG.20and a pair of opposed flat surfaces117, each having a stem119or120.

An internal, generally cylindrically shaped surface118surrounds valve opening114as shown inFIG.20. Each valving member112,113provides opposed stems119,120. Each valving member112,113rotates between opened and closed positions by rotating upon stems119,120. Each of the stems119,120is mounted in a stem opening90of tool body34at positions61,62and63,64as shown inFIG.22.

InFIG.19, valving member122,123is similar in configuration and in sizing to the valving members43,44,45of the preferred embodiment ofFIGS.1-17, with the exception of a portion that has been removed which is indicated in phantom lines inFIG.19. The milled or cut-away portion of the valving member112,113is indicated schematically by the arrow121. Reference line122inFIG.19indicates the final shape of valving member112,113after having been milled or cut. InFIGS.20and21, a beveled edge at123is provided for each valving member112,113.

When a valving member112,113is in the closed position ofFIG.22, flow arrows124indicate the flow of fluid through the tool body34bore51and more particularly in the outer channel72as indicated inFIG.22.

InFIG.23, the lower valving member113has been rotated to an open position as indicated schematically by the arrow134, having been rotated with tool74. In this position, fins73now block the flow of fluid in outer channel72. Flat surface115now faces upwardly. In this position, the cut-away portion of valving member113that is indicated schematically by the arrow121inFIG.19now faces up. Sliding sleeve111drops downwardly as indicated schematically by arrows130when a valving member112or113is rotated to an open position (see valving member113inFIG.23). InFIG.22, a gap129was present in between upper valve112and sleeve111that is below the valve112. The sleeve111that is in between the valves112,113is shown inFIG.22as being filled with very small diameter balls or “frac-balls”102.

When valving member113is rotated to the open position ofFIG.23, the gap is now a larger gap, indicated as135. Gap135(when compared to smaller gap129) has become enlarged an amount equal to the distance121illustrated by arrow121inFIG.19. The frac-balls102now drop through valving member113as illustrated by arrows127inFIG.23. Arrows125,126inFIG.23illustrate the flow of fluid downwardly through gap135and in central channel71.

A sleeve111above a valving member112or113thus move up and down responsive to a rotation of that valving member112or113. Spacers28can be employed that extend from each sleeve111radially to slidably engage tool body34. InFIGS.20and21, each stem119,120can be provided with one or more annular grooves131that are receptive of o-rings60or other sealing material. As with the preferred embodiment ofFIGS.1-17, openings132in each stem119,120are receptive of pins99. Likewise, each stem119,120provides internally threaded openings133. Thus, the same connection for attaching a valving member112,113to tool body34can be the one shown inFIGS.1-17.

FIGS.27A-33show another embodiment of the apparatus of the present invention wherein the tool body136provides an upper sleeve140that differs in construction from the sleeve of the embodiments ofFIGS.1-26. Further, the tool body136ofFIGS.27A-33provides an indicator147that indicates to a user whether or not a ball or dart145,146has in fact been discharged from the tool body136. Further, the embodiment ofFIGS.27A-33provides specially configured inserts or sleeves160,163that are positioned below the lower valve113, this additional sleeve or insert160is configured to prevent a build-up of material within the flow bore51below lower valving member113.

InFIGS.27A-33, tool body136provides upper end portion137and lower end portion138. As with the embodiments ofFIGS.1-26, the tool body136can be formed similarly to the tool body34, having multiple sections35,36,37,38and139. The section139is similar to the section39ofFIGS.1-26. However, the section139is configured to accept sleeve or insert160and sleeve or insert163.

Sleeve140is similar to the sleeves111ofFIGS.18-26. The sleeve140provides a cap141that can be connected to the sleeve140using threaded connection142. Cap141provides one or more longitudinally extending and circumferentially spaced apart openings143. The cap141can also provide a tool receptive socket144that enables rotation of cap141, relative to sleeve140, using a tool (e.g. allen wrench) during assembly of cap141to sleeve140.

InFIGS.27B,28-33indicator147is shown. The indicator147indicates to a user whether or not a dart145,146has passed the indicator147, thus indicating a discharge of the dart145,146from the tool body136.

InFIGS.27B and28-33, indicator147provides a shaft148that extends horizontally relative to flow bore51of tool body136. Lever arm149moves between an extended position as shown inFIG.27Band a collapsed position as shown inFIG.29. The lever arm149is initially set in the extended position ofFIG.27Bby placing pin150behind spring151upper end154as shown inFIG.27B. Spring151thus holds the pin150in a generally vertical position by rotating shaft148so that arm149extends into flow bore51.

InFIG.28, upper valve112is shown supporting a first dart145. Lower valve113is shown supporting a second dart146. Operation is the same as was described with respect toFIGS.1-26. Lower valve113, is rotated to an open position as shown inFIG.29by rotating the valve113through about ninety degrees. Dart146then drops as indicated by arrow164inFIG.29. As the dart146travels downwardly, leaving valve113and moving toward lower end portion138of tool body136, the dart146engages lever arm149. The dart146continues to move downwardly, pushing the arm149to the retracted position ofFIG.29as illustrated by arrow165inFIG.29. In this position, the pin150deflects spring151until pin150assumes the position shown in phantom lines inFIG.32.

The spring151upper end portion154prevents the pin150from returning to the position ofFIG.28, as the pin is now being held in the position shown inFIG.29. Arrow152inFIG.32illustrates the travel of arm149from the extended position to the retracted position. An operator can then reset the indicator147by rotating the pin150to the position shown inFIG.30as illustrated by arrow153inFIG.30. This procedure can then be repeated for the upper and second dart145as illustrated inFIGS.30and31. InFIG.31, the upper valve112is moved to an open position. A working fluid is pumped into tool body136at upper end137. Flow moves downwardly in the tool body136as illustrated by arrows166. Flow travels through openings143in cap141as illustrated by arrows167inFIG.31. This downward flow moves the darts145,146downwardly.

Indicator147can be attached to tool body136as shown inFIG.33. A pair of recesses155,156on tool body136enable attachment of shaft148. The shaft148can be held in position using fasteners such as bolts, for example. Spring151can then be attached to tool body136at recess156using fasteners158such as bolts. Curved arrow157inFIG.33illustrates rotation of shaft148for moving arm149and pin150between the extended position ofFIG.30and the retracted position ofFIG.31. Arm149extends through slot159in the extended position ofFIGS.30,32,33.

FIGS.27C and32illustrate placement of insert/sleeves160,163. The sleeve160provides an upper end portion that is conically shaped or tapered. This tapered section161is placed just below lower valve113and aids in the efficient flow of fluid downwardly in the tool body136eliminating unnecessary accumulation of material such as cement. Annular shoulder162on tool body136enables support of lower insert163which is placed below upper insert160as shown inFIGS.27B and27C.

FIGS.34A-39show another alternate embodiment of the apparatus of the present invention, designated generally by the numeral170. Plug dropping apparatus170provides an apparatus that can be used for launching plugs into casing171. Casing171is typically larger diameter and can have a diameter as large as about 20 inches. Examples of casing diameters are: 9⅝ inches, 10¾ inches, 13⅜ inches and 20 inches. The casing171shown inFIGS.34-37has a casing bore or annulus172. The casing bore or annulus172is defined by casing171inside surface173, which is typically generally cylindrically shaped.

The apparatus170of the present invention is designed to launch larger diameter (e.g. between about nine (9) and nineteen (19) inches) plugs such as the plugs176,177shown into a section of casing171having a casing bore or annulus172. This is accomplished using a tool body (e.g.34) having a pair or more of valving members and a pair of more smaller darts of one or more of the embodiments shown inFIGS.1-33in combination with the connectors174,175and casing171. For example, inFIGS.34-37, a tool body34is shown having a lower section39that connects to a smaller connector174. In order to launch one of the larger diameter plugs176,177that are a larger diameter which is larger than the diameter of tool body34, a pair of connectors174,175are used. These include a smaller connector174that is attached to section39of tool body34and a larger connector175that forms a connection between the first, smaller connector174and the casing171. Other connectors can be used as an interface between tool body34and casing171.

In order to launch the larger diameter plugs176,177, a smaller diameter dart199is launched from the tool body34as shown and described in the embodiments ofFIGS.1-33. The dart199is configured to pass through the central channel or bore184of an upper or first plug176and connect with a sleeve194of the second or lower casing plug177. This connection of the first dart199with the second or lower casing plug177can be seen inFIG.35B. InFIG.36B, arrow200illustrates a downward movement of the combination of second casing plug177and dart199followed by pumped cement203.

InFIG.3A, cement203is pumped downwardly through tool body34to first casing plug176, passing through channel or bore184. Pumping of cement through tool body34and its valving members is described in more detail with respect toFIGS.1-33.

The sleeve194of the second casing plug177provides a beveled annular surface197at the sleeve enlarged lower end195. The sleeve upper end196can be generally cylindrically shaped, enabling the dart199to easily enter and lodge inside the sleeve194and the channel or bore193(seeFIG.35B). The dart199provides a domed or beveled annular surface201that seals and latches upon the beveled annular surface197as shown inFIGS.35B,36B. In this position, fluid pressure and the downwardly flowing cement203can be used to shear pin208and force the combination of dart199and plug177down into the casing171bore or annulus172(seeFIG.36B).

Once the combination of dart199and second casing plug177move downwardly as indicated by arrow200inFIG.36B, cement can follow. A volume of cement203or cement mixture203can be a part of the driving force that moves the plug and dart combination177,179downwardly as shown inFIG.36B. For cementing operations in a casing171, the combination of second casing plug177and dart199move down followed by the volume of cement203followed by the combination of casing plug176and another dart202(seeFIGS.38B,39). When the selected volume of cement203has been transmitted into the casing bore172behind second casing plug177and dart199, the dart202is launched from tool body34and connects with (e.g. seals and latches with) casing plug177(seeFIGS.38A,39). The dart202has a lower beveled annular surface or domed or hemispherical surface204that registers upon a beveled annular surface205of sleeve206(see arrow207inFIG.38B).

InFIGS.36B,37,38B, and39the mass cement or cement mixture203has been injected in between the plugs176,177.

The second dart202has a domed or hemispherical or beveled annular surface204that seals and latches with beveled annular surface205of sleeve206of casing plug176(seeFIG.38B). Arrow207inFIG.38Brepresent fluid pressure applied to the assembly of dart202and casing plug176which can be used to shear pin208, forcing plug176and dart202downwardly behind cement203(seeFIG.39). Shear pin208can be used to hold the sleeves194,206prior to launch. Fluid pressure applied to a dart and plug199,177or202,176can be used to shear pin208.

The following is a list of parts and materials suitable for use in the present invention.

PARTS LISTPart NumberDescription10oil well drilling structure11platform12derrick13top drive unit14flow line15ball/plug dropping head16string17sea bed/mud line18body of water19water surface20platform deck21lifting device22tubular member23well bore24surface casing25cement/concrete26formation27casing shoe28float valve29passageway30passageway31upper end32liner/production casing33lower end portion34tool body35section36section37section38section39section40larger diameter ball41dart42smaller diameter ball43first valving member44second valving member45third valving member46threaded connection47threaded connection48threaded connection49threaded connection50threaded portion51flow bore52sleeve53channel54stem55stem56sleeve57sleeve58plug59plug60o-ring61opening position62opening position63opening position64opening position65opening position66opening position67spacer68outer curved surface69flat surface70flat surface71central flow channel72outer flow channel73fin74tool75arrow76upper plug77lower plug78arrows79flow passage80cement81flow passage82arrow83fluid84opening85opening86smaller diameter section87arrow - fluid flow path88fastener89internally threaded opening90opening91fastener92bushing93external threads94sleeve95passageway/bore96fastener97internally threaded opening98opening99pin100arrows101space102frac-ball110ball/plug dropping head111sleeve112valving member113valving member114valve opening115flat surface116curved surface117flat surface118internal surface119stem120stem121arrow122reference line123beveled edge124arrow125arrow126arrow127arrow128spacer129smaller gap130arrow sleeve movement131annular groove132opening133internally threaded opening134arrow135larger gap136tool body137upper end portion138lower end portion139section140sleeve141cap142threaded connection143opening144tool receptive socket145dart146dart147indicator148shaft149lever arm150pin151spring152arrow153arrow154spring upper end155recess156recess157curved arrow158fastener159slot160insert/sleeve161conical/tapered section162annular shoulder163insert/sleeve164arrow165arrow166arrow167arrow170plug dropping apparatus171casing172casing bore/annulus173inside surface174smaller connector175larger connector176first casing plug177second casing plug178plug outer surface179annular rib180annular rib181annular rib182annular groove183annular groove184channel/bore185annular projection186annular shoulder187beveled annular surface188annular rib189annular rib190annular rib191annular groove192annular groove193channel/bore194sleeve195sleeve enlarged lower end196sleeve upper end197beveled annular surface198arrow199dart200arrow201beveled annular surface202dart203cement204domed/hemispherical/beveled lower end205beveled annular surface206sleeve207arrow208shear pin

All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.

The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.