GB2589815A - Telemetry safety & life of well monitoring system - Google Patents

Abstract

An apparatus for disposing telemetric equipment in drillpipes comprising a drill pipe 102 having an uppermost drill pipe joint when drilling commences, a riser, a continuous length of wire extending through the drill pipe from a bottomhole assembly to the uppermost drill pipe joint, the length of wire having a wet connector 122 at the bottomhole assembly, and having an acoustic receiver/transmitter at the uppermost drill pipe joint. The receiver/transmitter may be mounted to an ROV with positions it against the riser to listen for an acoustic transmission from a transmitter/receiver fitted into the drillpipe.

Description

Telemetry Safety & Life of well monitoring System The present invention relates to a telemetry system, in particular one disposed in a drillpipe.

The conventional manner of drilling a borehole comprises lowering a drill hit into the earth, the drill hit being powered, for instance, by the rotation of the drillpipe, or by fluids circulating through the drillpipe and thence back up to the surface through the space between the drillpipe and the borehole. The drillpipe is made up of sections, new sections being added periodically at the top of the drillpipe string to allow the drill bit to be lowered further.

Much useful data can be garnered from sensors included in the drillpipe, such as temperature and pressure. To retrieve this information at the surface requires some form of media to transmit it through. Known systems include using pressure waves through the circulating mud, and electromagnetic pulses. Better rates of transfer and less attenuation may be achieved however by using an electrical conducting element.

The simplest way of installing a conducting cable, or indeed any line, along the drillpipe string is to wait until drilling has ceased and lower a single length down the drillpipe string. Where it is necessary to take readings from instrumentation means before the drillpipe is completed however, the cable must be lowered into the drillpipe string, only to be withdrawn each time a new drillpipe section is added to the drillpipe string.

One known method comprises a drillpipe incorporating conducting elements. The conducting elements of adjoining sections of drillpipe are electrically connected by inductive contacts, Such a system is expensive, and liable to develop faults as a result of fluid contaminating the connection. Many telemetry systems rely upon a segmented cable running through the drillpipe, cable sections being added in order to allow fresh sections of drillpipe to be added.

Every connection between individual lengths of cable provides a further opportunity for faults to occur.

The object of the present invention is to provide an apparatus and method for disposing reliable telemetric equipment in drillpipes and the like in an efficient manner.

According to the present invention a continuous length of fibre optic cable is installed inside a riser to listen for an acoustic transmission from a transmitter fitted into the drillpipe.

According to the present invention a continuous length of fibre optic cable is installed inside a kill or choke line to listen for an acoustic transmission from a transmitter fitted into the drillpipe.

According to the present invention a acoustic receiver is lowered inside a kill Or choke line to listen for an acoustic transmission from a transmitter fitted into the drillpipe.

According to the present invention a acoustic receiver/transmitter is lowered outside of the riser to listen for an acoustic transmission from a transmitter fitted into the drillpipe.

According to the present invention a acoustic receiver/transmitter is Mounted to an ROY which positions it against the riser to listen for an acoustic transmission from a transmitter/reciever fitted into the drillpipe.

According to a further aspect of the invention, a wircline is installed 10 inside the drillpipe which transmits both power and telemetry from the drilling assembly to the acoustic transmitter/receiver.

According to a further aspect of the invention, the the acoustic transmitter can also received acoustic data, both in the drillpipe and in the device connected to surface.

According to a further aspect of the invention, acoustic trasnmitters mounted in the casing or riser can transmit data down to the bottom hole assembly.

According to a further aspect of the invention the fibre can be mounted inside the casing annulus and cemented in the well.

According to a further apect of the invention a second acoustic receiver / transmitter can be daisy chained to the first to enable more hole to be drilled while still being capable of transmiting data to surface, this is more relevant to short risers.

A telemetering system will now be described, by way of example, with reference to the drawings, of which; Figure 1 shows a side view of a offshore drilling unit with a riser attached to a subsea tree.

Figure 2a shows a section side view of a riser with one embodiment of the invention.

Figure 2b shows a section side view of a riser with a further embodiment of the invention.

Figure 2c shows a section side view of a riser with a further embodiment of the invention.

Figure 2d shows a section side view of a riser with a further embodiment of the invention.

Figure 2e shows a section side view of a riser with a further embodiment of the invention.

Figure 3 is a section end view of a riser pipe, all other pipes and connections removed for clarity.

Figure 4 Is a similar view to figure 3 Figure 4a is an exploded view highlighted in figure 4 Figure 5 Is a similar view to figure 4 showing a different cable installation process.

Figure 6 Is a similar view to figure 5 in a subsequent stage of cable deployment to figure 5.

Figure 7 Is a similar view to figure 6 in a subsequent stage of cable deployment to figure 6.

Figure 8 is a section side view XX of figure 7.

Figure 9 is a similar view to figure 3 of a different embodiment.

Figure 10 is a section side view of two joints of wellbore casing, connected 15 with a casing coupling, with an external mounted armoured fibre optic cable.

Figure 11 Is a similar view to figure 9 with an additional cable added which includes an acoustic transmitter.

Figure 12 Is a section side view of a land drilling rig with the last casing installed and cemented.

Figure 13, Is a similar view to figure 11 with the drilling assembly deployed into the well on drillpipe.

Figure 14 Is a similar view to figure 12 with a cable deployed inside the drillpipe, on the lower end is a wet connector, and the upper end an acoustic transmitter/receiver for hi directional telemetry to the drilling assembly.

Figure 15 is a similar view to figure 13, with new hole being drilled and the transmitter/receiver lower in the well and transmitting to the fibre attached to the outside of the casing cemented into the well.

Figure 16 is a similar view to figure 15, with new hole being drilled and the transmitter/receiver lower in the well and transmitting to the fibre attached to either the inside of the riser of the offshore drilling unit..

Figure 17 is a section side view of the drillpipe with a landing sub for the upper cable termination to be landed, and allow it to transmit its acoustic data.

Figure 18 is a similar view to figure 17 with a extension cable attached to upper connection of the cable landed in the landing sub.

Figure -19 is a side sction through a different landing sub illustrating an 20 embodiment of the invention that can both transmit and receive acoustic data.

Figure 1 shows a semi submersible drilling unit 1, connected to a sub sea tree 2 via a drilling riser 3. On the lower most end of the drilling riser is a lower drilling module 4 and an upper drilling module 5. The rig in this example is held in place using mooring lines 6 and anchors 7. In deepwater the water depth could be between 6 and 10,00011, making it ideal for this technology.

Referring to figures 2 to 4 and 9 there are shown section side view and section end view of the drilling riser 3a and 3b. Connected together using a flange joint 10. The two additional tubes shown are choke 11 and kill 12 lines. Because the risers are aligned with a flange, it is possible to have either welded or bonded to the inside of the riser a channel 12 which contains a reCCSS 13 and 13' for a metal clad 17 fibre optic cable 16 to be installed in recess 13, and a electric armoured cable 19 to be installed in rcccss 13'. The recess is chamfered 14 to allow the fibre to be easily installed and narrow neck 15 which is slightly smaller than the fibre, it has to be displaced open to accept the metal clad fibre, this is achieved by incorporating thin slots 18 which allow thc slot opening to flex. Once the metal clad fibre is inside the slot, it cannot fall out, but have to be pulled out during the retrieval process. Alternatively, the metal clad fibre can have a guide shoe fitted to its lower end and it can be lowered into a closed hole 27, and the profile 28 containing the hole 27 could formed in such a shape to minimise it being impacted by rotating drillpipe, this would have the benefit that it could be installed concurrent with running in the drillpipe, so no rig time would he lost.

In addition, the electric cable 19 could power a small flush mounted acoustic transmitter attached to its lower most end, this could be lowered at the same rate as the drillpipe is lowered, so keeping the acoustic transmitter adjacent to the acoustic receiver installed into the drillpipe.Alternatively, an acoustic transmitter and receiver 30, could be lovered on a slick line 31 inside the choke or kill line 11,12 to transmit and receive acoustic data to and from the drillpipc receiver/transmitter, the signal in this case has to pass through two steel tube walls, that of thc choke or hill line and the riser itself. A further alternative would be a set of transmitters/recievers 32 daisy chained together, and mounted into hole(s) 33 machined in the riser, and powered by a cable 34 onto which would also be multiplexed the signal data, so at certain posiions the receiver/transmitter in the drillpipe would be able to receive/transmit acoustic data.

Altcnatively, the acoustic transmitter / receiver could be raised and lowered adjacent to the riser 200. The cable 201 would support the acoustic transmitter / receiver 200 and contain both power and telemetry cables to power the device and transmit data both from surface and back to surface., because there is not size limitations, this device could be as large as required. It could also incorporate a simple tic bar 202 to keep it in close proximity to the riser, this could be fitted using an ROV. In fact an ROV could also be used to carry, power and transmit the data back to and from surface.

Alternatively, the acoustic transmitter/receiver 212 could be fitted to the arm 211 of an ROY 210, and the ROY could be lowered down the side of the riser 213 to be stationed as close to the drillpipe transmitter 214 as possible, using its unbilical 215 to both power the transmitter/receiver 212 and transmit the data to and from surface.

Referring to Figures 5 to 8 is show another embodiment of the fibre optic cable, which is lowered into the riser wrapped around an electrically insulated tensile carrying member 20 which at its lower most end has a tool 30. Once at the bottom of the riser, a cutter is dropped from surface which results in the fibre optic cable opening out 21 to form a flat arrangement. Thc flat construction includes a metal clad tube 22 with a gel surrounding the fibre. And two U shaped thin metal continuous strips 23, 24 which are spot welded to the inner surface of the riser by a welding wheel 25 of the tool 30. The tool 30 pushes the flat cable 21 to the inner surface of the riser using a spring mechnaish 31 and a roller wheel 32. As the spiked welding wheel rotates it spikes the flat cable and the tip penetrates the metal foil to make a circuit with the inside surface of the riser, and a low voltage high current discharge creates the weld.

Additionally, post manconda, it is very important and advantageous to know what exactly in inside the riser, the fibre optic cable could be constructed to be pressure sensitive as well as listen for potential gas or other potential hazards Referring to figures 10 and 11 there is shown a section side view of two joints of casing 40, 41 screwed together with a coupling 42. An armoured fibre optic cable 43 is banded 44 to the casing and run in with the casing and cemented in place. A second cable 45 can also he run and terminated in the coupling 42 with a sealed olive termination 46. Inside the coupling is a pizoelectric 47 transmitter, which is loused via a horned exit 48 to direct its tone to the inside of the casing. There would be many of these transmitters daisy chained together and all would transmit, so depending upon where the upper termination 56 was located inside the casing or riser, it would change from transmitting mode to listening mode, and then send the signal it received down the wireline to the bottom hole assembly. This signal maybe used for example to change the direction of drilling based on updated reservoir data.

Referring to figures 12 to 16 there is shown 4 stages in the application of this technology. The casing described in figure 9 and 10 has been installed into the well. The casing 40, 41 etc go from total depth to surface, on the outside of these casings is run the metal clad fibre optic cable 43. The casing is then cemented 50 as normal.

The bottom hole assembly 51 which consists of a bit, rotary steering system, orientation and directional drilling componets and logging tools, on the top of this is a electrical wet connector pin 52 looking up. This whole assembly is run in the hole on drill collars and drill pipe 53. When the required length is run in the well (typically the expected length of hole it is anticipated the bit will drill) a wireline 54 is run into the drillpipe and a wet connector 55 on its end docks into the wet connector 52 looking up. At the surface end of the wireline 54 is an upper termination 56, this is hung off in a hanger sub installed onto the drillpipe at this point.. The upper termination 56 recieves both power and signals from the bottom hole assembly. The telemetry it receives it converts into an audiable signal and tranmits this continuously 57. The continuous fibre 43 in the annulus of the casing or the riser of the offshore drilling unit, is interrogated using a surface unit capable of listening to sound and vibrations at every meter along the fibre. It is capable of transmitting significant /inanities of data from the bottom hole assembly using proven modem technology (Kbits vs bits), regardless of the drilling operation, i.e. Drilling ahead, wiper trip etc. In addition, by incorporating the fibre behind the casing, it provides a permanent monitoring feature, so can be used for reservoir monitoring, and Or gas and fluid migration behind the casing.

Referring to figures 17 to 19 there is show a section side view through two embodiments of the drillpipe landing sub. The sub has a lower pin 100 and upper box 101 which enables it to be installed between two joints of drillpipe 102. The sub has a section in its middle that extends as a web 103 from the side wall 104. A horse shoe flow by area 105 provides the maximum flow by area. A hole 106 through the web section is in the centre line 107 of the drill pipe. On the rig floor, the wireline 108 is lowered into the drillpipe, on its lower end, not shown is a electrical wet connector, which docks onto the othcr half of the electrical wct connector at the top of the bottom hole assembly. The upper termination 109 lands on a shoulder 110, and the wireline is either fully supported, or excess wireline is lowered into the drillpipe so that it is resting on the internal wall of the drillpipe, so that it is out of the main flow of the drilling mud. A collet 111 locks into a profile 112 and retains the upper termination in the bore 106. Inside the upper termination, the wireline inside the cable is terminated into a piezoelectric assembly 113, which receives power and telemetry from the bottom hole assembly. The piezoelectric assembly generates an acoustic modem signal which is attenuated to the outside of the drillpipe via a horn or trumpt shaped 114 recess.

In the event the section of open hole drilled is longer than the riser or casing, an extension to a new hanging sub can be run inside the drillpipe and docked onto of the wircline hanger already installed in the drillpipe. On the upper half of the wireline hanger is a electrical connection 115, isolated by seals 116 mounted in a sleeve 117. The extension wireline, is lowered from the drill floor and a funnel on its lower end 118 abd a centraliser 119 allows it to dock onto the cone 120 looking up. Inside the upper wireline, lower connector 121, is an electrical wet connector 122 isolated by seals 123 and a spring 124 loaded cover 125, dielectric oil 126 surrounds the electrical contacts.. The telemetry and power can continue up to the new transmitter fitted at the top of the new wireline 127.

An alternative arrangement is shown in figure -19, in which a module 130 can both transmit and receive acoustic signals to and from outside the drillpipe. The module 130 can process the electrical signals from the bottom hole assembly, and convert to acoustic signals, or receive acoustic signals and convert them to electrical signals and send down the cable to the bottom hole assembly, thus achieving fast bi directional communications. The module 130 connects via a wire 131 to an electrical connector on the cable 132, which is isolated from the drilling fluid by seals 133. The module is inside a chamber 134 which is filled with dielectric oil 135 and pressure compensated via a piston 136

Claims (1)

1. CLAIMS1. An apparatus for disposing reliable telemetric equipment in drillpipes comprising a drill pipe having an uppermost drill pipe joint when drilling commences a riser a continuous length of wire extending through the drill pipe from a bottomhole assembly to the uppermost drill pipe joint the length of wire having a wet connector at the bottomhole assembly, and having an acoustic receiver/transmitter at the uppermost drill pipe joint 2 An apparatus according to claim I wherein the acoustic receiver/transmitter is lowered outside of the riser to listen for an acoustic transmission from a transmitter fitted into the drillpipe.3 An apparatus according to any previous claim wherein the acoustic receiver/transmitter is mounted to an ROV which positions the acoustic receiver/transmitter against the riser to listen for an acoustic transmission From a transmitter/reciever fitted into the drillpipe.4 An apparatus according to any previous claim wherein a continuous length of fibre optic cable is installed inside a riser to listen for an acoustic transmission from a transmitter fitted into the drillpipe.5 An apparatus according to any previous claim wherein a continuous length of fibre optic cable is installed inside a kill or choke line to listen for an acoustic transmission from a transmitter fitted into the drillpipe.6 An apparatus according to any previous claim wherein an acoustic receiver is lowered inside a kill Or choke line to listen for an acoustic transmission from a transmitter fitted into the drillpipe.7 An apparatus according to any previous claim wherein acoustic trasnmitters mounted in the casing or riser can transmit data down to the bottom hole assembly.8 An apparatus according to claims 4 or 5 wherein the fibre can be mounted inside thc casing annulus and cemented in the well.9. An apparatus according to any previous claim wherein a wireline is installed inside the drillpipe which transmits both power and telemetry from the drilling assembly to the acoustic transmitter/receiver.10. An apparatus according to any previous claim wherein the acoustic transmitter can also received acoustic data, both in the drillpipe and in the device connected to surface.11. An apparatus according to any previous claim wherein a second acoustic receiver / transmitter can be daisy chained to the first to enable more hole to be drilled while still being capable of transmiting data to surface.