GB2598912A

GB2598912A - Drill rig tube delivery apparatus and method

Info

Publication number: GB2598912A
Application number: GB2014668.4A
Authority: GB
Inventors: Larkin Brendan
Original assignee: Oiltech Group Ltd
Current assignee: Oiltech Group Ltd
Priority date: 2020-09-17
Filing date: 2020-09-17
Publication date: 2022-03-23
Also published as: GB202014668D0

Abstract

A tube delivery apparatus, for delivering tubes to, and receiving them from, a drill platform comprises a base frame 210 on which is pivotally mounted a ramp 220. The ramp is for engagement with a drill platform. Also mounted on the base frame, for slidable movement with respect to the base frame, is a tube support 230 for receiving a single drill tube or multiple tubes connected together end to end. A tube support is mounted for movement against the ramp 220, and a proximal tube support end is pivotally connected to a link member for propping the proximal tube support. At least one of the tube support and link member is mounted for movement with respect to a guide track 240, which track is inclined downwardly away from the ramp.

Description

Drill Rig Tube Delivery Apparatus and Method The present invention relates to a drill rig tube delivery apparatus and method, and is concerned particularly, although not exclusively, with apparatus and a method for delivering tubes between a non-vertical storage facility and a drill platform.

Drilling rigs used in the discovery and extraction of hydrocarbons typically comprise at least: a derrick, having a mast for supporting a lifting apparatus for lifting drill tubes and a rotary drive for turning the drill tubes in the well, a platform on which are mounted draw works for hoisting the lifting apparatus, a "roughneck" device for coupling and uncoupling drill tubes, a casing tong for connecting and disconnecting casing tubes, a power unit, a blow-out preventer and a storage rack for the drill tubes. Portable drilling rigs are known in which much of the essential apparatus may be stowed in a compact configuration for transportation, for example on the back of one or more lorries.

The process of drilling an oil well is complex. Each time a well is drilled there is a requirement to move hundreds of tonnes of equipment and the power to drive it. It has been common for the setting up of an oil rig to take between a few days to two weeks or so. Often this is downtime (a time where the contractor receives no funds or limited funds). It is therefore important that this process, known as 'rig up' is minimised.

The choice of site is an ongoing process and is made by geologists with knowledge of the rocks that lie below, which may be 10,000 ft (3000m), or more. A classic choice would be over a dome-shaped fold (revealed by seismic survey). This is often a gamble and would rely on oil and gas having migrated to the top of the dome and accumulated there, millions of years ago, and been restrained by a layer of impermeable rocks above. Once there, the layers will have separated, with gas on top of the oil and ground water below, all at very high pressures.

The procedure commences by drilling a hole using a relatively large drill to penetrate the soft surface layer down to 1000 ft (300m), or so. The hole is built carefully. A drill bit, on the end of a drill string (of tubes) is rotated from the surface ("drill floor") by a top drive unit, via a quill, within a mast on the rig.

Down below, the drilling bits break the hole into fragments and in order not to choke the hole a special fluid ("mud") is pumped down the inside of the drill string to pre-vent the bit from overheating and to carry the cuttings back to the surface. The returning mud is collected in a "mud bucket" and is then pumped through fine mesh screens known as "shakers", where the coarse cuttings are removed. Then the mud is pumped through separators and settling bits to get rid of the finer materials. The mud can then be recycled down the hole.

As long as the drill bit is turning the mud must be kept circulating through the top drive, the quill, the drill pipe, the drill bit and up the outside of the hole. However, at intervals of depth (typically every 30' for some drill tubes or e.g. every 45' for others) the drill string will need an additional pipe. The drilling stops to do this and the supply of mud is shut off by an isolating valve in the top drive. At this point a part of the pipe remains protruding upwards from the drill floor (this part being called the "stick-up") and the pipe below is supported by slips (wedge grips) which take the mass of the pipe below.

The next drill pipe is brought in and is collected by the quill drive, elevated and restrained back to well centre. The new pipe is then gently sat on the stick-up and the quill lowers to come clear of the tool joint (the end part of the pipe that contains the thread for connection to another pipe -about 6" or 150mm). At this point a handling tong moves in, grips the stick-up, then grips the tool joint on the new pipe and connects the two pipes. This process is called "make-up". The two pipes are threadedly connected together at a pre-set torque to maintain the integrity of the string. The upper end of the new pipe is connected to the quill drive and the top drive valve is opened. The drilling recommences and the mud pumping continues. The procedure is repeated.

In the case of a typical well this operation takes place two hundred times or more before the intended bottom of the hole is reached.

Typically, when the hole reaches 1000 ft (with upwards of twenty lengths of drill pipe) a well casing, comprising a series of connected metal tubes, is run into the hole. This process is essential to stabilise the well, i.e. to prevent the softer formation caving in.

At this point the drill string is removed from the hole. The process is known as "tripping out" and there is no rotation of the drill string or pumping of mud. Elevators, including manually or hydraulically operated gripping jaws, lift out the disconnected drill pipes (one, two or three at a time) while the mass of the remaining drill string is supported by mechanically operated wedges called "power slips" at the well centre. Then, the drill pipes are pushed out for delivery to the storage rack. This process is called "breaking out". (NB: whenever drill pipes are to be re-introduced into the drilled hole, the opposite process -known as "tripping in" is performed).

The casing tubes are then loaded individually onto loader arms and positioned onto the drill floor. Each casing tube is lifted off by the travelling assembly. A so-called "stab arm" collects the pipe and gently eases the casing to the well centre. The casing tube is then lowered through the rotary drive, with centralisers fitted at regular intervals, and held by slips. The elevator then collects the next casing tube and the two tubes are threadedly connected. This procedure is repeated until e.g. 25 casing tubes have been inserted into the well (25 casings of 40' equals 1000 ft (300m)) leaving the casing just clear of the bottom of the drilled hole.

The next task is to cement the casing in place. To do this, cement is pumped down the hole through the casing under pressure. When it reaches the bottom of the hole, it forces the mud and cement back up the outside of the casing (hence the reason for the bottom clearance) and back to the surface. At that point the pumps are stopped and the cement is allowed to set.

The top of the casing is now capped at the top (ground level) by a BOP (Blow Out Preventer) which comprises a group of safety valves to protect the rig against high pressure. In the event of extreme pressure, the BOP seals off the well, closing the gap between the drill string and the casing. As the drilling goes deeper, thereby incurring the possibility of even higher pressures, a series of rams are included within the BOP.

Once the BOP is fitted, drilling can recommence. This next phase of the drilling will use a smaller diameter drill bit. The drill bit is connected (and torqued) to the first drill pipe, and the drill pipes are tripped in, e.g. 25 lengths of 45' pipe (i.e. 1000'), until the drill bit reaches the bottom of the pre-drilled hole. The quill is then reconnected and drilling, and the pumping of mud, is resumed.

The precise formation of the casing string is planned by geologists and geo-physicists and may involve ever decreasing sizes of casing tube (for example 13%", 104", 94", 8", 7"). These will dictate different drill bits and the number of cementing operations required.

Drill bit wear must also be taken into account. As the drill bits drill through a harder formation (e.g. hard rock, granite, etc.) they may wear out more frequently. Drill bits may last as little as a few hours. This becomes noticeable by a loss of cutting power which occurs when the drill bit becomes dull (and the well makes a distinctive noise). The only solution is to pull the whole string (tripping out), change the drill bit and put the new string back in the hole (tripping in).

The next stage involves drilling into the gas and oil and care must be taken to get the correct consistency and chemical composition of the mud to cope with the pressure. Often, prior to going into the formation, an instrument probe is added to the string (meaning full string trip-out, fit probe, trip in). The probe will contain measuring devices which measure certain electrical, acoustical, and radio-active characteristics of the different layers which are sent back to the surface and recorded. At this point an estimation may be made as to how much oil and gas the dome may contain. This information is then analysed to ascertain the full potential of the well. Often additional wells are drilled nearby, allowing a three-dimensional analysis of the dome.

Drilling rigs usually require a team of skilled workers to operate them, but in recent times there has been a move towards mechanising, semi-automating and even fully automating many of the functions that were previously carried out manually by operatives. The drive for automation has, in some cases, led to the design of rigs in which a single operative is able to control and oversee all, or almost all, of the key functions using monitors and electronic controls, usually from within the safety and relative comfort of a control room located on the rig. However, fully automated rigs can be prohibitively expensive for many operating companies and are therefore not widely used, particularly in smaller drilling operations.

Many drilling rigs feature a storage rack for the drill tubes, and casing tubes that is arranged substantially vertical and within, or at least adjacent, the platform.

However, in the interests of improving automation, some drillings rigs feature a tube storage rack that is non-vertical, i.e. the tubes are arranged in a substantially horizontal configuration close by the platform. During tripping-in, the drill tubes are retrieved, either individually or as pre-connected "doubles" or "triples" and delivered to the drill floor via a ramp. Once at the drill floor they are lifted to the well centre by the lifting apparatus. The reverse is true during tripping-out.

Any saving of time during these processes directly increases the efficiency of the operation and can lead to substantial cost savings.

Embodiments of the present invention aim to provide apparatus and a method for providing tubes to a drilling rig in which at least some of the foregoing problems are addressed.

The present invention is defined in the attached independent claims, to which reference should now be made. Further, preferred features may be found in the sub-claims appended thereto.

According to one aspect of the present invention, there is provided tube delivery apparatus for delivering tubes between a storage facility and a drill platform of a drilling rig, the apparatus comprising: a base, a ramp having a first, lower ramp end mounted on the base and a second, upper ramp end positionable adjacent a drill platform, a tube support having a distal tube support end, mounted for movement against the ramp between the first and second ramp ends, and a proximal tube support end pivotally connected to a link member for propping the proximal tube support end when the distal tube support end is spaced from the lower ramp end, wherein at least one of the tube support and link member is mounted for movement with respect to a guide track, which track is inclined downwardly away from the ramp.

In a preferred arrangement the tube support is mounted for movement with respect to a first guide track. The first guide track may be inclined downwardly with respect to the ramp. The first guide track may be arranged to extend downwardly in a direction away from the ramp, more preferably downwardly away from a base of the ramp.

The tube support may comprise a channel profile having a bottom and a side wall, more preferably having a substantially deep contour wherein the tube is held in place as it is delivered between a storage facility and a drill platform. The percentage of retention of the tube on the tube support is calculated using a line from the centre of the tube to a lip of the tube support. If a tube support is too shallow and the percentage retention of the tube is too small, it is unsafe. If the tube support is too deep and the percentage retention of the tube is too large, it is a problem getting the tube off the tube support and onto the drilling platform.

The link member may be mounted for movement with respect to a second guide track. The second guide track may be inclined downwardly with respect to the ramp. The second guide track may be arranged to extend downwardly in a direction away from the ramp, more preferably downwardly away from a base of the ramp.

The tube support and/or the link member are preferably mounted for rolling movement with respect to the guide track. Alternatively, or in addition, the tube support and/or the link member may be mounted for sliding movement with respect to the guide track.

The tube support may be mounted for rolling motion with respect to the ramp. Alternatively, or in addition, The tube support may be mounted for sliding motion with respect to the ramp.

The apparatus is preferably provided with a cable/rope for raising and/or lowering the tube support with respe= to the ramp. The cable/rope is preferably under the control of a winch, which may be powered, for example by a motor.

The tube support preferably has a pushing device arranged in use to urge a tube to move along the tube support, wherein the pushing device may be overridden automatically in the event of a predetermine level of resistance. The tube support may have a pulling device arranged in use to urge a tube to move along the tube support.

The apparatus preferably includes a crane, more preferably a gantry crane, for collecting a tube from a storage facility and placing the tube on the tube support.

The apparatus may be arranged to deliver multiple, preferably connected, tubes together in the same operation.

According to a second aspect of the present invention, there is provided a tube handling method for delivering tubes between a storage facility and a drill platform of a drilling rig, the method comprising: placing a tube on a tube support, urging the tube support along a ramp adjacent the drill platform, the tube support comprising a distal tube support end, mounted for movement against the ramp between the first and second ramp ends, and a proximal tube support end pivotally connected to a link member for propping the proximal tube support end when the distal tube support end is spaced from the lower ramp end, wherein at least one of the tube support and link member is mounted for movement with respect to a guide track, which is inclined downwardly away from the ramp and urging the tube along the tube support.

The method may comprise delivering multiple tubes together, which tubes are connected end to end, for example as doubles or triples.

The invention may include any combination of the features or limitations referred to herein, except such a combination of features as are mutually exclusive, or mutually inconsistent.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 shows schematically, in perspective view, a land-based oil drilling rig; Figure 2 is a schematic side view of a tube delivery apparatus in a preliminary starting/loading configuration, according to an embodiment of the present invention; Figure 3a is a schematic perspective view of a ramp of the apparatus secured to a drilling platform of a rig; Figure 3b is a schematic perspective view of part of the tube delivery apparatus showing the ramp in a folded configuration; Figure 3c is a schematic cross view of a tube support; and Figures 4-9 are schematic side views of the apparatus in various phases of a tube delivery operation.

Turning to Figure 1, this shows generally at 1000 a land-based oil drilling rig. The rig includes a mast 100 for supporting a lifting apparatus 120 for lifting drill tubes T, a platform 130 on which are mounted a rotary top drive 140 for turning the drill tubes in the well and a roughneck 150 for coupling and uncoupling tubes and, beside the mast, a storage rack 160 for the drill tubes.

Drill tubes T are collected from smart storage bins 170 in the storage rack by a gantry crane 180 and delivered up a ramp 190 to the drill floor, e.g. for coupling to a down-well drill string (not shown). The tubes may be stored connected together in doubles or triples or may be stored as singles and connected together in the storage facility. The tubes may be delivered to the drill floor as singles or as multiple tubes joined together.

Figure 2 shows a tube delivery apparatus generally at 200 for delivering tubes to, and receiving them from, the drill platform (not shown in Figure 2). The tube delivery apparatus 200, shown in Figure 2 in a tube-loading configuration, comprises a base frame 210 on which is pivotally mounted a ramp 220. The ramp is for engagement with a drill platform (not shown) as will be described below. Also mounted on the base frame, for slidable movement with respect to the base frame, is a tube support 230 for receiving a single drill tube or multiple tubes connected together end to end.

Figures 3a and 3b show schematically the ramp 220 which in use engages with a drill platform 300. The ramp is of box section steel and includes concealed grooves 222 for accommodating wire rope for hauling the tube support, as will be described below, driven by a motor winch 224. Hydraulic cylinders 226 lift the ramp from a folded/transportation configuration, as shown in Figure 3b, to an extended/operational configuration, as shown in Figure 3a, in which retention members 228 at an upper end engage with mooring posts 310 of the drill floor.

Figure 3c shows schematically, in section, the tube support 230 with a substantially deep contour 231 on which a drill tube T is guided along during tube delivery (as will be described below).

Figure 4 shows the apparatus shortly after the tube support 230 has started to rise. A pair of drill tubes (not shown) are connected together end-to-end and rest on the tube support 230. A distal end 230a of the tube support rolls upwards along the ramp on a rollers R, being pulled by the wire rope, under the action of the winch, in the direction of Arrow A. As the tube support rises up the ramp, a proximal end rolls in a first guide track 240, on rollers R in the direction of Arrow B. Simultaneously, a prop member 250, pivotally connected to the proximal end of the tube support 230, also rolls within a second guide track 260 on rollers R until it reaches a stop 262. Further hauling of the tube support 230 up the ramp then causes the proximal end to rise out of the guide track 240, as shown in Figure 5, in the direction approximately indicated by Arrow C, pushing against the prop member abutting the stop 262.

Figure 6 depicts the point at which the distal end of the tube support has reached the top of the ramp. In Figure 7 the tube support is urged forwards onto the platform (not shown) in a direction indicated by Arrow D, by continued pulling of the wire rope in the direction indicated generally by Arrow E. Once the tube support is sufficiently across the platform a pusher 270 urges the tubes forward in the direction of Arrow D. The tubes are then attached to lifting gear (not shown) which is used to take them to the well centre for coupling to the drill string.

The prop member 250 is important as it ensures that the tube support 230, and hence the tubes themselves, are presented at the platform at a shallow angle (a) (Figure 7) to make it easier for an operative to connect them to the lifting gear.

Figure 8 shows the tube support shortly after a lowering operation has begun. The distal end is moving in a direction indicated generally by Arrow F and the proximal end in a direction indicated generally by Arrow G under the control of motor winch 224, assisted by gravity.

In the configuration shown in Figure 9, the proximal end of the tube support 230 has lowered sufficiently to re-enter the guide track 240. By this stage the prop member 250 has begun rolling back along the guide track 260.

Importantly, the guide tracks 240 and 260 slope downwardly in a direction away from the ramp so that, as the tube support is lowered, gravity may assist in returning it to a substantially horizontal starting position for the loading of another tube or multiple of tubes. Either, or preferably both, tracks should slope downwardly from the ramp to assist in returning the tube support to the starting, or loading, position. If needed, a further winch (not shown) may be provided to urge the proximal end of the tube support along the guide track to its furthest extent, away from the ramp, while the tube support is returning to the loading position shown in Figure 2.

The drill tubes T are somewhat protected from falling out of the tube support by the sides of the substantially deep contour 231 (Figure 3c). Ideally the tube resides centrally and in the bottom of the contour, and most importantly restrained against the walls of the contour. Failure to do this makes the tube unstable and it may roll sideways during momentum or environmental loads (side winds). The operation means that a variety of tubes with different diameters use this route. The diameters vary from 3.5" to 20". The substantially deep contour 231 ensures that all tubes have an acceptable percentage retention.

Pusher 270 can also be overridden to prevent the drill tubes T from bowing should an obstruction occur when they are being delivered between a storage facility and the drill platform. If a compressive load is added to the tube (during pushing) and there is an obstacle (a block or push in the opposite direction), the tube would try to bow. If the tube bows and releases (eg the obstacle moves) the tube can become unpredictable and may fall off the "skate" (tube support 230). By overriding the pusher, the external push in the opposite direction can be relieved hydraulically hence ensuring the tube cannot bow (and subsequently jump off).

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be understood that the applicant claims protection in respect of any patentable feature or combination of features referred to herein, and/or shown in the drawings, whether or not particular emphasis has been placed thereon.

Claims

CLAIMS1.A tube delivery apparatus for delivering tubes between a storage facility and a drill platform of a drilling rig, the apparatus comprising: a base, a ramp having a first, lower ramp end mounted on the base and a second, upper ramp end positionable adjacent a drill platform, a tube support having a distal tube support end, mounted for movement against the ramp between the first and second ramp ends, and a proximal tube support end pivotally connected to a link member for propping the proximal tube support end when the distal tube support end is spaced from the lower ramp end, wherein at least one of the tube support and link member is mounted for movement with respect to a guide track, which track is inclined downwardly away from the ramp.
2.A tube delivery apparatus according to Claim 1 wherein the tube support is mounted for movement with respect to a first guide track.
3.A tube delivery apparatus according to Claims 1 and 2 wherein the first guide track is inclined downwardly with respect to the ramp, in a direction away from the ramp.
4.A tube delivery apparatus according to preceding claims wherein the first guide track is arranged to extend downwardly away from a base of the ramp.
5.A tube delivery apparatus according to Claims 1 or 2 wherein the tube support comprises a channel profile having a bottom and a side wall.
6.A tube delivery apparatus according to Claim 5 wherein the tube support comprises a substantially deep contour.
7.A tube delivery apparatus according to Claim 1 wherein the link member is mounted for movement with respect to a second guide track.
8.A tube delivery apparatus according to Claim 7 wherein the second guide track is inclined downwardly with respect to the ramp, in a direction away from the ramp.
9.A tube delivery apparatus according to Claim 8 wherein the second guide track is arranged downwardly away from a base of the ramp.
10. A tube delivery apparatus according to preceding claims wherein the tube support is mounted for rolling movement with respect to the guide track.
11. A tube delivery apparatus according to preceding claims wherein the tube support is mounted for sliding movement with respect to the guide track.
12. A tube delivery apparatus according to preceding claims wherein the link member is mounted for rolling movement with respect to the guide track.
13. A tube delivery apparatus according to preceding claims wherein the link member is mounted for sliding movement with respect to the guide track.
14. A tube delivery apparatus according to preceding claims wherein the tube support is mounted for rolling motion with respect to the ramp.
15. A tube delivery apparatus according to preceding claims wherein the tube support is mounted for sliding motion with respect to the ramp.
16. A tube delivery apparatus according to preceding claims wherein the apparatus is provided with a cable for raising and lowering the tube support with respect to the ramp.
17. A tube delivery apparatus according to Claim 16 wherein the cable is under the control of a winch.
18. A tube delivery apparatus according to preceding claims wherein the tube support has a pushing device arranged in use to urge a tube to move along the tube support.
19. A tube delivery apparatus according to Claim 18 wherein the pushing device is optionally overridden.
20. A tube delivery apparatus according to preceding claims wherein the tube support has a pulling device arranged in use to urge a tube to move along the tube support.
21. A tube delivery apparatus wherein the apparatus includes a crane, for collecting a tube from a storage facility and placing the tube on the tube support.
22. A tube delivery apparatus according to preceding claims wherein the apparatus is arranged to deliver multiple, connected, tubes together in the same operation.
23. A tube handling method for delivering tubes between a storage facility and a drill platform of a drilling rig, the method comprising: placing a tube on a tube support, urging the tube support along a ramp adjacent the drill platform, the tube support comprising a distal tube support end, mounted for movement against the ramp between the first and second ramp ends, and a proximal tube support end pivotally connected to a link member for propping the proximal tube support end when the distal tube support end is spaced from the lower ramp end, wherein at least one of the tube support and link member is mounted for movement with respect to a guide track, which is inclined downwardly away from the ramp and urging the tube along the tube support.
24. A tube handling method according to Claim 23 wherein the method delivers multiple tubes together, connected end to end.