AU2010264270A1

AU2010264270A1 - Method and apparatus for monitoring fluids

Info

Publication number: AU2010264270A1
Application number: AU2010264270A
Authority: AU
Inventors: Robert Bain; Hugh Mackenzie
Original assignee: Paradigm Flow Services Ltd
Current assignee: Paradigm Flow Services Ltd
Priority date: 2009-06-25
Filing date: 2010-06-18
Publication date: 2012-01-12
Also published as: US20120160329A1; GB2471549B; GB201010265D0; IN2012DN00700A; EP2446110A2; GB2471549A; WO2010150000A2; WO2010150000A3; BRPI1014842A2; GB0910978D0; CN102459807A

Abstract

A method and apparatus for monitoring a fluid that is to be transported through a fluid conduit within a hydrocarbon exploration and production installation is described. A monitoring zone is established upstream of the fluid conduit configured such the fluid supply to the fluid conduit is introduced via the monitoring zone. The fluid supply within the monitoring zone is monitored for the occurrence of events detrimental to the flow of the fluid supply through the fluid conduit. Monitoring the fluid supply prior to entering the fluid conduit allows for the early detection of an event detrimental to the flow of the fluid supply e.g. a chemical reaction indicative of corrosion of the fluid conduit or the formation of a potential blockage within the fluid conduit. In this way the risk of costly blockages or structural failure occurring within the fluid conduit is reduced.

Description

WO 2010/150000 PCT/GB2010/051014 1 1 Method and Apparatus for Monitorinq Fluids 2 3 The present invention relates to a method and apparatus for use in the hydrocarbon 4 exploration and production industry and in particular to a method and apparatus for 5 monitoring a fluid that is to be transported through a fluid conduit. The monitoring of a fluid 6 to be transported through a fluid conduit provides a dynamic indication of the occurrence 7 of detrimental effects for the fluid flow within the conduit. The described method and 8 apparatus have particular application for preventing blockages within fluid umbilicals, 9 although the methods and apparatus may also be adapted for monitoring fluids for the 10 occurrence of detrimental effects within pipelines, wellbores and risers. 11 12 During the production and transportation of hydrocarbons, it is common for the interiors of 13 fluid conduits, including pipelines, wellbores, risers and umbilicals, to become fouled. This 14 fouling can lead to the build up of layers of debris or particulate matter on the inside of 15 conduits, which reduces the effective inner diameter (ID) of the conduit and thus reduces 16 the flow rate. Fouling can also produce blockages in the fluid conduits which completely 17 prevent fluid flow. 18 WO 2010/150000 PCT/GB2010/051014 2 1 A fluid umbilical is a bundled collection of steel and/or thermoplastic tubing and electrical 2 cabling. Typically they are employed to transmit chemicals, hydraulic fluids, electric 3 power, and two-way data communication and control signals between surface production 4 facilities and subsea production equipment. Umbilicals typically range up to 10 inches 5 (254 mm) in diameter, with internal tubes ranging from 0.5 inch to 1 inch (12.7 mm to 25.4 6 mm) in diameter. A dynamic umbilical is the portion of the umbilical that is suspended 7 from a semi-submersible vessel to the seabed, where it is coupled to a static section of the 8 umbilical. In a typical umbilical, the multiple internal conduits are twisted together into a 9 helical rope-like structure in order to increase the tensile strength. This is a particularly 10 important consideration for the dynamic umbilical section since it must withstand stresses 11 due to its own weight and the dynamic loading from currents. 12 13 Examples of some of the most frequently transmitted chemicals through umbilicals within 14 the hydrocarbon exploration and production industry include: scale inhibitors; corrosion 15 inhibitors; methanol, ethanol, ethylene glycol, mono ethylene glycol, MEG (examples of 16 hydrate inhibitors); industrial methylated spirits; wax inhibitors and pour point depressants 17 (PPD); low dosage hydrate inhibitors (LDHIs); asphaltene inhibitors and dispersants; flow 18 improvers and surfactants; biocides; H 2 S scavengers; and demulsifiers. 19 20 The relatively small diameters of the internal tubes within the subsea umbilical, in 21 combination with the fact that their helical path arrangement significantly increases the 22 frictional drag experienced by objects inserted into the internal tubes, means that 23 umbilicals are particularly prone to blockages. Such blockages completely prevent fluid 24 transmission through the umbilical and so can cause considerable disruption to production 25 activities. Furthermore, the helical path arrangement of the internal conduits means that 26 conventional cleaning equipment is often prohibited from being inserted to attempt to clear 27 a blockage. If a blockage cannot be removed then this results in obvious time and cost 28 implications for the operator. It is estimated that the costs incurred in replacing a typical 29 subsea fluid umbilical run into several millions of pounds. 30 31 In order to mitigate the risk of blockages forming within umbilicals it is known in the art to 32 provide the internal tubes with a filter at its entrance. Such filters do help prevent certain 33 particulates and other debris from entering the internal tubing. However, in practice it is 34 found that the major contributing factor to the formation of blockages within a fluid 35 umbilical is human error, either through the poor design of the chemical bunkering WO 2010/150000 PCT/GB2010/051014 3 1 systems, unsuitable methodologies being employed in offshore environments or even 2 faulty chemical compatibility testing being carried out. For example, if an operator 3 accidentally allows incompatible fluids to be transmitted down the same internal tube then 4 coagulation or flocculation may take place so resulting in blockages within the umbilical. 5 Some examples of known incompatible fluid combinations include: 6 1) Scale inhibitors and methanol or glycols. If the scale inhibitor is water based (as is 7 normally the case) then methanol or a glycol will precipitate the inhibitor; 8 2) Pour point depressants and methanol or glycols. When the level of methanol or 9 glycol is above a certain level then precipitation of some polymer PPDs occurs; 10 3) Asphaltene inhibitors and methanol; 11 4) Asphaltene dispersants and polar solvents (e.g. alcohols, glycols or water); 12 5) Flow improvers for water and polar solvents; 13 6) Flow improvers for oil and any of the other above listed transmitted chemicals; 14 7) H 2 S scavengers and methanol or organic solvents; and 15 8) Biocides and methanol. 16 17 A further detrimental effect that occurs within fluid conduits is the onset of corrosion. The 18 effects of corrosion can be exacerbated by the chemical nature of the fluid supply being 19 transported through the conduit. Corrosion can ultimately lead to structural failures within 20 a fluid conduit and therefore it is obviously beneficial to be able to monitor the detrimental 21 effects of corrosion within a fluid conduit. 22 23 It is therefore an object of an aspect of the present invention to provide a method and 24 apparatus for monitoring a fluid that is to be transported through a fluid conduit so as to 25 provide a dynamic indication of the occurrence of detrimental effects for the fluid flow 26 within the conduit. 27 28 It is a further object of an aspect of the present invention to provide a method and 29 apparatus for monitoring the formation of a blockage within a fluid conduit system. 30 31 A yet further object of an aspect of the present invention to provide a method and 32 apparatus for monitoring the level of corrosion within a fluid conduit system. 33 WO 2010/150000 PCT/GB2010/051014 4 1 The described method and apparatus is applicable to a wide range of fluid conduit 2 systems used in the hydrocarbon exploration and production industry, and in particular to 3 fluid umbilicals. 4 5 Summary of Invention 6 7 According to a first aspect of the present invention there is provided a method for 8 monitoring a fluid supply to be transported through a fluid conduit located within a 9 hydrocarbon exploration and production installation, the method comprising the steps of: 10 - providing a monitoring zone upstream of the fluid conduit; 11 - introducing the fluid supply to the fluid conduit via the monitoring zone; and 12 - monitoring the fluid supply within the monitoring zone so as to detect the 13 occurrence of one or more events detrimental to the flow of the fluid supply through 14 the fluid conduit. 15 16 It is advantageous to monitor the fluid supply prior to entering the fluid conduit as this 17 allows for the early detection of an event detrimental to the flow of the fluid supply e.g. a 18 chemical reaction indicative of corrosion of the fluid conduit or the formation of a potential 19 blockage within the fluid conduit. In this way the risk of costly blockages or structural 20 failure occurring within the fluid conduit is significantly reduced. 21 22 Most preferably the step of monitoring the fluid supply within the monitoring zone 23 comprises the step of detecting solids or solidification within the fluid supply. 24 25 Preferably the method further comprises the step of shutting off the fluid supply to the fluid 26 conduit when solidification is detected. Shutting off the fluid supply to the fluid conduit 27 allows an operator to check the installation to see if a non-compatible chemical supply has 28 been introduced to the fluid supply. 29 30 Optionally the step of detecting solids or solidification within the fluid supply comprises 31 monitoring a pressure differential across a filter located within the monitoring zone. A 32 change in the pressure differential across the filter is indicative of a change in the viscosity 33 within the fluid supply and hence a possible contamination of the fluid supply. 34 WO 2010/150000 PCT/GB2010/051014 5 1 Preferably the step of shutting off the fluid supply to the fluid conduit occurs when the 2 pressure differential across the filter is outside of a predetermined tolerance value for the 3 fluid supply. 4 5 Most preferably the step of monitoring the pressure differential across the filter further 6 comprises the step of correlating the monitored pressure differential with a temperature of 7 the fluid supply. By correlating the pressure differential across the filter with the 8 temperature of the fluid supply reduces the risk of erroneous contamination events being 9 detected. 10 11 Optionally, the step of detecting solids or solidification within the fluid supply comprises the 12 step of monitoring the water content of the fluid supply. 13 14 Preferably the step of shutting off the fluid supply to the fluid conduit occurs when the 15 water content of the fluid supply is outside a predetermined tolerance value for the fluid 16 supply. 17 18 Optionally, the step of detecting solids or solidification within the fluid supply comprises the 19 step of monitoring a particulate or debris content of the fluid supply. 20 21 Preferably the step of shutting off the fluid supply to the fluid conduit occurs when a 22 density or mass of the particulate or debris content within the fluid supply is outside a 23 predetermined tolerance value for the fluid supply. 24 25 If the fluid supply to the fluid conduit is shut down then an alarm may be activated to notify 26 an operator of the shut down event. Optionally an automated electronic notification may 27 also be sent to an appropriate preselected person notifying them of the shut down event. 28 29 Preferably the step of monitoring the fluid supply within the monitoring zone further 30 comprises the step of analysing the quality or purity of the chemical composition of the 31 fluid supply. 32 33 Optionally the step of monitoring the fluid supply within the monitoring zone further 34 comprises the step of monitoring the rate of flow of the fluid supply. 35 WO 2010/150000 PCT/GB2010/051014 6 1 2 Preferably the method further comprises the step of notifying an operator of the risk of a 3 blockage occurring within the fluid conduit when the quality or purity of the chemical 4 composition of the fluid supply is outside a predetermined tolerance value. 5 6 Optionally the method further comprises the step of recording information relating to one or 7 more of the monitored parameters. Recording information regarding fluid cleanliness, 8 viscosity, water content, differential pressure, absolute pressure, temperature and fluid 9 flow rates allows for historical data reviews to be generated. 10 11 According to a second aspect of the present invention there is provided a method for 12 monitoring a fluid supply to be transported through a fluid umbilical, the method comprising 13 the steps of: 14 - providing a monitoring zone upstream of the fluid umbilical; 15 - introducing the fluid supply to the fluid umbilical via the monitoring zone; and 16 - monitoring the fluid supply within the monitoring zone so as to detect the 17 occurrence of one or more events detrimental to the flow of the fluid supply through 18 the fluid umbilical. 19 20 Embodiments of the second aspect of the invention may comprise preferred and optional 21 features of the first aspect of the invention and vice versa. 22 23 According to a third aspect of the present invention there is provided a fluid monitoring unit 24 for monitoring a fluid supply to a fluid conduit, the fluid monitoring unit comprising a 25 monitoring zone and a sensor, the sensor providing a means for detecting the occurrence 26 of one or more events within the monitoring zone detrimental to the flow of the fluid supply 27 through the fluid conduit, wherein the monitoring zone is configured to provide upstream 28 fluid cooperation with an entrance of the fluid conduit. 29 30 By having the monitoring zone configured to provide upstream fluid cooperation with an 31 entrance to the fluid conduit allows the fluid monitoring unit to dynamically monitor the fluid 32 supply prior to entering the fluid conduit. This allows for the early detection of potential 33 blockage forming scenarios and so significantly reduces the risk of costly blockages 34 occurring within the fluid conduit. 35 WO 2010/150000 PCT/GB2010/051014 7 1 Most preferably the sensor comprises a filter located within the monitoring zone and a 2 pressure detector arranged to monitor the pressure differential of the fluid supply across 3 the filter. 4 5 Preferably the sensor further comprises a thermometer arranged to provide a means for 6 the fluid monitoring unit to correlate changes in the monitored pressure differential across 7 the filter with temperature changes of the fluid supply. 8 9 Alternatively, or in addition, the sensor comprises a hygrometer arranged to monitor the 10 water content of the fluid supply. 11 12 Alternatively, or in addition, the sensor comprises a particulate sensor arranged to monitor 13 the fluid supply transmitted through the monitoring zone for the presence of particulate or 14 debris. 15 16 The particulate sensor may comprise an optical particulate sensor. The particulate sensor 17 may comprise a passive-induction particulate sensor. 18 19 Alternatively, or in addition, the sensor comprises a UV spectrometer arranged to monitor 20 the chemical composition of the fluid supply transmitted through the monitoring zone. 21 22 Alternatively, or in addition, the sensor comprises a flow meter arranged to monitor the 23 rate of flow of the fluid supply. 24 25 Most preferably the fluid monitoring unit comprises a computer processing unit that 26 provides a means for controlling the sensor. The computer processing unit also provides a 27 means for the fluid monitoring unit to transmit and receive data. 28 29 Preferably the computer processing unit generates an output signal if the pressure 30 differential of the fluid supply across the filter is outside of a predetermined tolerance 31 value. 32 33 The computer processing unit may also generate an output signal if the water content 34 within the fluid supply is outside of a predetermined tolerance value. 35 WO 2010/150000 PCT/GB2010/051014 8 1 The computer processing unit may also generate an output signal if a density or mass of 2 the particulate or debris content within the fluid supply is outside a predetermined 3 tolerance value. 4 5 The computer processing unit may also generate an output signal if the quality or purity of 6 the chemical composition of the fluid supply is outside a predetermined tolerance value. 7 8 According to a fourth aspect of the present invention there is provided a fluid monitoring 9 unit for monitoring a fluid supply to a fluid umbilical, the fluid monitoring unit comprising a 10 monitoring zone and a sensor, the sensor providing a means for detecting the occurrence 11 of one or more events within the monitoring zone detrimental to the flow of the fluid supply 12 through the fluid umbilical, wherein the monitoring zone is configured to provide upstream 13 fluid cooperation with an entrance of the fluid umbilical. 14 15 Embodiments of the fourth aspect of the invention may comprise preferred and optional 16 features of the third aspect of the invention and vice versa. 17 18 According to a fifth aspect of the present invention there is provided a hydrocarbon 19 exploration and production installation, the installation comprising at least one supply 20 conduit that provides a means for fluid communication between a fluid source and a fluid 21 conduit, and a fluid monitoring unit in accordance with the third aspect of the present 22 invention, wherein the fluid monitoring unit is located within the supply conduit upstream of 23 the fluid conduit. 24 25 Preferably the installation further comprises a pump located between the fluid source and 26 the fluid monitoring unit. 27 28 Optionally the installation further comprises a shut off valve located between the fluid 29 monitoring unit and the fluid conduit. 30 31 Preferably an output signal from the fluid monitoring unit is employed as a feedback signal 32 to activate a shut down of the pump. The output signal may also be employed as a 33 feedback signal to activate closure of the shut off valve. 34 WO 2010/150000 PCT/GB2010/051014 9 1 Preferably the installation further comprises an operations control module connected to the 2 fluid monitoring unit so as to provide a means for monitoring and recording output data 3 from the fluid monitoring unit. 4 5 According to a sixth aspect of the present invention there is provided a hydrocarbon 6 exploration and production installation, the installation comprising at least one supply 7 conduit that provides a means for fluid communication between a fluid source and a fluid 8 umbilical, and a fluid monitoring unit in accordance with the fourth aspect of the present 9 invention, wherein the fluid monitoring unit is located within the supply conduit upstream of 10 the fluid umbilical. 11 12 Embodiments of the sixth aspect of the invention may comprise preferred and optional 13 features of the third fourth and fifth aspects of the invention and vice versa. 14 15 Brief Description of Drawinqs 16 17 Aspects and advantages of the present invention will become apparent upon reading the 18 following detailed description of example embodiments and upon reference to the following 19 drawings in which: 20 21 Figure 1 presents a schematic diagram of a surface production facility, that provides fluid 22 communication with an umbilical, and which incorporates fluid monitoring units in 23 accordance with an embodiment of the present invention; and 24 25 Figure 2 presents a schematic diagram of the fluid monitoring units of Figure 1. 26 27 In the description which follows, like parts are marked throughout the specification and 28 drawings with the same reference numerals. The drawings are not necessarily to scale 29 and the proportions of certain parts have been exaggerated to better illustrate details and 30 features of embodiments of the invention. 31 32 Detailed Description 33 34 In order to provide understanding of the various aspects of the present invention a 35 schematic diagram of a surface production facility, generally depicted by the reference WO 2010/150000 PCT/GB2010/051014 10 1 numeral 1, is presented in Figure 1, while Figure 2 presents a schematic diagram of a fluid 2 monitoring unit 2 employed with the surface production facility 1. 3 4 The surface production facility 1 can be seen to comprise four supply conduits 3 that 5 provide a means for fluid communication between a corresponding fluid source 4 and an 6 umbilical 5 via a topside umbilical termination unit (TUTU) 6. In the presently described 7 embodiment the fluid sources comprise a corrosion inhibitor 4a (one such suitable 8 corrosion inhibitor being that sold by Champion Technologies under the trade mark 9 Scortron* G10000), a scale inhibitor 4b (one such suitable scale inhibitor being that sold 10 by Champion Technologies under the trade mark Gyptron* SA11 ON), methanol 4c and a 11 wax inhibitor 4d (one such suitable wax inhibitor being that sold by Champion 12 Technologies under the trade mark Flexoil* WM1 840). 13 14 Within each supply conduit 3 is located a metering pump 7, a fluid monitoring unit 2 and a 15 shut-off valve 8. Each metering pump 7 is employed to regulate the pressure flow of the 16 fluid within its respective supply conduit 3 and hence into an internal tube of the umbilical 17 5. The fluid monitoring units 2 are located between the metering pumps 7 and the TUTU 6 18 and are employed to monitor one or more parameters associated with the transported fluid 19 before it is pumped into the umbilical 5. A feedback connection 9 provides a means for 20 the fluid monitoring unit 2 to stop its respective metering pump 7 and/or to close the 21 respective shut-off valve 8 when the occurrence of a detrimental effect for the fluid flow 22 within the umbilical 5 is detected e.g. a potential blockage forming scenario is detected or 23 significant levels of corrosion are detected, further details of which are provided below. 24 25 An electricity supply 10 provides a dedicated power source for each of the fluid monitoring 26 units 2. Each fluid monitoring unit 2 is also connected to an operations control module 11 27 which may be located within the surface production facility 1. Optionally, the operations 28 control module 11 is connected to a remote operations control module 12 that provides a 29 means for remotely monitoring and controlling the fluid supplies into the umbilical 5. 30 Communication to and from the facility and within the facility itself may be by RS232, 31 Ethernet or wireless means. 32 33 From Figure 2 each fluid monitoring unit 2 can be seen to comprise a monitoring zone in 34 the form of a conduit 13 through which the fluid supply is transmitted such that the 35 monitoring zone provides a means for upstream fluid cooperation with an entrance of an WO 2010/150000 PCT/GB2010/051014 11 1 internal tubing of the umbilical 5. Located within the monitoring zone 13 is a filter 14 which 2 provides an initial means for preventing particulates and other debris from entering the 3 internal tubing of the umbilical 5. The fluid monitoring unit 2 further comprises a pressure 4 sensor 15 that provides a means for measuring the pressure differential of the fluid supply 5 across the filter 14 or the absolute pressure of the fluid supply within the monitoring zone 6 13 (an Able Instrumentation Differential Pressure Gauge Model 126 being one such 7 suitable pressure sensor), a thermometer 16 that provides a means for measuring the 8 temperature of the fluid supply (an Able Instruments eight wire, one series temperature 9 switch being one such suitable thermometer), and a hygrometer 17 that provides a means 10 for measuring the water content within the fluid supply (an Able Instruments HTF dewpoint 11 sensor being one such suitable hygrometer). Optionally, the fluid monitoring unit 2 further 12 comprises a particulate or flocculation sensor 18 (an Able Instruments Model 980 series 13 dual beam Photometer being one such suitable particulate sensor); a UV spectrometer 19 14 (an Able Instruments Model 960 UV-Analyzer being one such suitable UV spectrometer); 15 and a flow meter 20 that provides a means for accurately monitoring the rate of flow of the 16 fluid before it enters the internal tubing of the umbilical 5. The flow meter may be a 17 positive displacement flow meter, for example a helical screw flow meter or a rotary piston 18 flow meter since both meter types provide accurate readings at relatively low flow rates. 19 20 Each of the sensors 15, 16, 17, 18, 19 and 20 are connected to a CPU 21 which provides 21 a means for controlling the sensors 15, 16, 17, 18, 19 and 20, processing the measured 22 data and relaying the data on to the control modules 11 and/or 12. 23 24 In the presently described embodiment the filter 14 comprises a two micron absolute filter, 25 however the filter size may be changed depending on expected flow rates within the 26 system. For the presently described surface production facility 1 the fluid supply flow rates 27 range from a minimum flow rate of 40 ml/min to a maximum flow rate of 1000 ml/min. 28 Corresponding pressures through the system range from 0 to 5000psi. 29 30 It is preferable for the distance between the fluid monitoring unit 2 and the shut-off valve 8 31 to be sufficient that on the fluid monitoring unit 2 detecting the occurrence of a detrimental 32 effect for the fluid flow within the umbilical the shut-off valve 8 can be closed before the 33 fluid supply passes its physical location. 34 WO 2010/150000 PCT/GB2010/051014 12 1 The above described fluid monitoring units 2 allow for various ways to detect the 2 occurrence of solidification within supplied fluids and for analysing the quality of supplied 3 fluids. The onset of solidification within the fluid supply can be indicative of coagulation or 4 flocculation caused by chemical reactions between different fluids or the use of low quality 5 or purity fluids, and/or the formation of solid particulates or debris as a result of corrosion 6 within the umbilical itself. The various techniques will now be described in further detail. 7 8 Monitorinq Pressure Deferential 9 10 The first method employs the pressure sensor 15 to monitor a pressure differential across 11 the filter 14. The pressure differential is correlated with the temperature of the fluid, as 12 measured by the thermometer 16. This correlation may take place directly within the 13 pressure sensor 15, the CPU 21 or more preferably within the control modules 11 or 12. A 14 change in the viscosity within the fluid supply is detected as a corresponding change in the 15 pressure differential across the filter 14. If the change in pressure differential is outside of 16 a predetermined tolerance value for that particular fluid, and does not correlate with a 17 corresponding temperature change, as detected by the thermometer 16, then this is 18 indicative of a chemical reaction causing coagulation or flocculation, for example the 19 inadvertent mixing of a scale inhibitor and methanol. Coagulation or flocculation can lead 20 to the onset of a blockage within the umbilical 5 and so in such circumstances the fluid 21 monitoring unit 2 would activate an alarm within the control module 11 and/or 12 and 22 preferably provide for the automatic shut down of the metering pump 7 in conjunction with 23 the closing of the corresponding shut-off valve 8. This would allow the operator to check 24 the facility 1 to see if a non-compatible chemical combination had been set up in error 25 sufficiently early in the process so as to avoid the occurrence of a costly blockage. 26 27 Monitorinq Water Content 28 29 The second method for detecting potential on set of a blockage is achieved via the 30 employment of the hygrometer 17. The hygrometer 17 is set to detect the presence of 31 water within the fluid supply between 0% and 100% using a small electrical current. A 32 predetermined value, with acceptable tolerance levels, is provided for a particular fluid 33 supply. Activation of the alarms and/or the shutting down of the fluid supply, as previously 34 described, again results if the detected water level moves out with the predetermined 35 tolerance levels. For example, the water content for a water-based fluid supply e.g. a WO 2010/150000 PCT/GB2010/051014 13 1 biocide may be of the order of 80% with an accepted tolerance level of ±0.5%. If a 2 solvent, for example a wax inhibitor, were to be introduced to the water-based fluid supply 3 then the water content may fall to around 78% thus triggering the alarms and/or the 4 shutting down of the supply line. Alternatively, the water content for a solvent-based fluid 5 supply e.g. an ashphaltene inhibitor may be of the order of 0% with an accepted tolerance 6 level of +0.5%. If a water based fluid, for example an H 2 S scavenger or even simply rain 7 water were to be introduced to the solvent-based fluid supply then the water content may 8 rise to above 0.5% thus triggering the alarms and/or the shutting down of the supply line. 9 10 What is important for the operation of the above solidification diagnostic is the 11 establishment of a base water level content for a fluid supply and an appropriate tolerance 12 level. The hygrometer 17 then allows for changes in the water content of the fluid supply 13 to be monitored and appropriate action taken if this exceeds the predetermined tolerance 14 value. 15 16 It is preferable for the fluid monitoring unit 2 to also be capable of measuring and recording 17 the absolute pressure, temperature and rate of fluid flow of the fluid supply. The pressure 18 sensor 15, the thermometer 16 and the flow meter 20 in conjunction with the control 19 modules 11 and/or 12 can facilitate all of these diagnostics. 20 21 Particle Analysis 22 23 The employment of the particulate sensor 18 provides a means for detecting the presence 24 of particulates or debris with the fluid supply. The particulates or debris may be of a type 25 that is transmitted directly into the monitoring zone 13 or are formed as a result of a 26 chemical reaction within the monitoring zone 13 e.g. via corrosion. 27 28 The particulate sensor 18 preferably comprises an optical sensor whereby one or more 29 light sources and a photodetector are arranged to provide sensing points within the 30 monitoring zone 13 e.g. an Able Instruments Model 980 series dual beam Photometer. 31 Particulates or debris passing through sensing points then acts to scatter the light from the 32 light source onto the photodetector which is thereafter transformed into a pulsed signal. 33 The number of pulses per unit time is proportional to the density of particulates or debris 34 presents. The pulse signal is then converted into a voltage output for relaying to the 35 control modules 11 and/or 12.

WO 2010/150000 PCT/GB2010/051014 14 1 2 Alternatively, or in addition to the optical particulate sensor, the particulate sensor 18 may 3 comprise a type that employs a combination of passive-induction and protected-probe 4 technologies (a Baumer Process Instrumentation conductivity sensor ISLO5x being one 5 such suitable sensor). As particles or debris flow near and around the probe, minute 6 currents are dynamically induced within the probe. These currents can then be processed 7 to provide an absolute output that is substantially linear to the mass of the particulates or 8 debris present. 9 10 Optical particulate sensors are preferable for use with oil based fluids or solvents e.g. wax 11 inhibitor while they are less effective when used with water based fluids e.g. biocides. In 12 such fluids it is preferable to employ the passive induction type of sensors. 13 14 In a similar manner to that described above a predetermined particulate or debris level is 15 defined for a particular fluid supply. If the mass of the particulate or debris exceeds this 16 predetermined value then the fluid monitoring unit 2 activates the corresponding alarms 17 and/or shuts down the fluid supply. 18 19 As well as the fluid monitoring units 2 being configured to operate or trigger an alarm 20 and/or shut down the fluid supply upon exceeding one or more predetermined parameters, 21 the control modules 11 or 12 may also be configured to automatically e-mail an 22 appropriate preselected person about the potential problem within the facility 1. This 23 facility has particular application in the following circumstances. 24 25 UV Spectroscopv 26 27 During the operation of the surface production facility 1 there are times when it is required 28 to be shut down. On occasion this shut down period may last several weeks. On 29 restarting the surface production facility 1 it can be found to have developed a blockage 30 even although no obvious contamination of the fluid has occurred. 31 32 It has been recognised by the inventors that the source of the formation of such blockages 33 lie within the inherent quality or purity of the fluid being transported i.e. if the fluid quality or 34 purity is below a predetermined value and then the fluid is allowed to remain static within 35 the umbilical then a blockage may form.

WO 2010/150000 PCT/GB2010/051014 15 1 2 The employment of the UV spectrometer 19 provides a means for analysing the chemical 3 composition of a fluid within the monitoring zone 13 and thus provide an indication if it falls 4 below a predefined quality or purity level. In such circumstances the fluid monitoring unit 2 5 notifies the control modules 11 and/or 12 that the fluid should not be allowed to remain 6 static within the umbilical 5. 7 8 If a shut down event of the surface production facility 1 occurs during this period then 9 subsequent periodic reminders may be sent to the operator of the surface production 10 facility 1 notifying them that unless pumping of the fluid is re started then they are heading 11 for the occurrence of a blockage within the umbilical 5. 12 13 The above described method and apparatus provide a means for protecting the integrity of 14 a fluid conduit and in particular a fluid umbilical. The method and apparatus allow for a 15 reduction in the vulnerability of these expensive assets due to human error by providing a 16 means for continuous dynamic monitoring of the injected fluid supplies and providing for 17 automated pump shut down when potential detrimental effects for the fluid flow within the 18 fluid umbilical are detected e.g. blockage forming circumstances. Significantly, the fluid 19 monitoring units provide a proactive method that prevents the formation of blockages 20 rather than allowing for a reactive method to be employed in response to the detection of a 21 blockage, as is the case for known prior art systems. 22 23 By performing real time particle analysis and monitoring chemical compatibilities, via 24 pressure, temperature, water and particle content measurements, and UV spectroscopy 25 round the clock analysis can be performed. This allows for trends within the facility to be 26 built up for individual umbilicals, or other fluid conduits, and so enables the activation of 27 alarms or automated shut downs, as and when appropriate. 28 29 The adapted facility also allows for periodic integrity reviews to be carried out wherein 30 information regarding fluid cleanliness (NAS rating), viscosity, water content, differential 31 pressure, absolute pressure, temperature and flow rates can be displayed in real time or 32 downloaded for historical data reviews. 33 34 The foregoing description of the invention has been presented for purposes of illustration 35 and description and is not intended to be exhaustive or to limit the invention to the precise WO 2010/150000 PCT/GB2010/051014 16 1 form disclosed. The described embodiments were chosen and described in order to best 2 explain the principles of the invention and its practical application to thereby enable others 3 skilled in the art to best utilise the invention in various embodiments and with various 4 modifications as are suited to the particular use contemplated. Therefore, further 5 modifications or improvements may be incorporated without departing from the scope of 6 the invention as defined by the appended claims. 7

Claims

Claims

1 ) A method for monitoring a fluid supply to be transported through a fluid conduit located within a hydrocarbon exploration and production installation, the method comprising the steps of: - providing a monitoring zone upstream of the fluid conduit; - introducing the fluid supply to the fluid conduit via the monitoring zone; and - monitoring the fluid supply within the monitoring zone so as to detect the occurrence of one or more events detrimental to the flow of the fluid supply through the fluid conduit.

2) A method for monitoring a fluid supply as claimed in claim 1 wherein the step of monitoring the fluid supply within the monitoring zone comprises the step of detecting solids or solidification within the fluid supply.

3) A method for monitoring a fluid supply as claimed in claim 2 wherein the method further comprises the step of shutting off the fluid supply to the fluid conduit when solidification is detected.

4) A method for monitoring a fluid supply as claimed in either of claims 2 or 3 wherein the step of detecting solids or solidification within the fluid supply comprises monitoring a pressure differential across a filter located within the monitoring zone.

5) A method for monitoring a fluid supply as claimed in claim 4 wherein the step of shutting off the fluid supply to the fluid conduit occurs when the pressure differential across the filter is outside of a predetermined tolerance value for the fluid supply.

6) A method for monitoring a fluid supply as claimed in either of claims 4 or 5 wherein the step of monitoring the pressure differential across the filter further comprises the step of correlating the monitored pressure differential with a temperature of the fluid supply.

7) A method for monitoring a fluid supply as claimed in any of claims 2 or 6 wherein the step of detecting solids or solidification within the fluid supply comprises the step of monitoring the water content of the fluid supply. 8) A method for monitoring a fluid supply as claimed in claim 7 wherein the step of shutting off the fluid supply to the fluid conduit occurs when the water content of the fluid supply is outside a predetermined tolerance value for the fluid supply.

9) A method for monitoring a fluid supply as claimed in any of claims 2 or 8 wherein the step of detecting solids or solidification within the fluid supply comprises the step of monitoring a particulate or debris content of the fluid supply.

10) A method for monitoring a fluid supply as claimed in claim 9 wherein the step of shutting off the fluid supply to the fluid conduit occurs when a density or mass of the particulate or debris content within the fluid supply is outside a predetermined tolerance value for the fluid supply.

1 1 ) A method for monitoring a fluid supply as claimed in any of claims 3 or 8 wherein the method further comprises the step of activating an alarm to notify an operator that the fluid supply to the fluid conduit has been shut down.

12) A method for monitoring a fluid supply as claimed in any of claims 3 or 9 wherein the method further comprises the step of sending an electronic notification to a preselected person notifying them that the fluid supply to the fluid conduit has been shut down.

13) A method for monitoring a fluid supply as claimed in any of the preceding claims wherein the step of monitoring the fluid supply within the monitoring zone further comprises the step of analysing the quality or purity of the chemical composition of the fluid supply.

14) A method for monitoring a fluid supply as claimed in claim 13 wherein the method further comprises the step of notifying an operator of the risk of a blockage occurring within the fluid conduit when the quality or purity of the chemical composition of the fluid supply is outside a predetermined tolerance value. 15) A method for monitoring a fluid supply as claimed in any of the preceding claims wherein the step of monitoring the fluid supply within the monitoring zone further comprises the step of monitoring the rate of flow of the fluid supply.

16) A method for monitoring a fluid supply as claimed in any of the preceding claims wherein the method further comprises the step of recording information relating to one or more of the monitored parameters.

17) A fluid monitoring unit for monitoring a fluid supply to a fluid conduit, the fluid monitoring unit comprising a monitoring zone and a sensor, the sensor providing a means for detecting the occurrence of one or more events within the monitoring zone detrimental to the flow of the fluid supply through the fluid conduit, wherein the monitoring zone is configured to provide upstream fluid cooperation with an entrance of the fluid conduit.

18) A fluid monitoring unit as claimed in claim 17 wherein the sensor comprises a filter located within the monitoring zone and a pressure detector arranged to monitor the pressure differential of the fluid supply across the filter.

19) A fluid monitoring unit as claimed in either of claims 17 or 18 wherein the sensor further comprises a thermometer arranged to provide a means monitoring a temperature of the fluid supply.

20) A fluid monitoring unit as claimed in any of claims 17 to 19 wherein the sensor comprises a hygrometer arranged to monitor the water content of the fluid supply.

21 ) A fluid monitoring unit as claimed in any of claims 17 to 20 wherein the sensor comprises a particulate sensor arranged to monitor the fluid supply transmitted through the monitoring zone for the presence of particulate or debris.

22) A fluid monitoring unit as claimed in claim 21 wherein the particulate sensor comprises an optical particulate sensor.

23) A fluid monitoring unit as claimed in claim 21 wherein the particulate sensor comprises a passive-induction particulate sensor. 24) A fluid monitoring unit as claimed in any of claims 17 to 23 wherein the sensor comprises a UV spectrometer arranged to monitor the chemical composition of the fluid supply transmitted through the monitoring zone.

25) A fluid monitoring unit as claimed in any of claims 17 to 24 wherein the sensor comprises a flow meter arranged to monitor the rate of flow of the fluid supply.

26) A fluid monitoring unit as claimed in any of claims 17 to 25 wherein the fluid monitoring unit further comprises a computer processing unit that provides a means for controlling the sensor.

27) A fluid monitoring unit as claimed in claim 26 wherein the computer processing unit provides a means for the fluid monitoring unit to transmit and receive data.

28) A fluid monitoring unit as claimed in either of claims 26 or 27 wherein the computer processing unit generates an output signal if the pressure differential of the fluid supply across the filter is outside of a predetermined tolerance value.

29) A fluid monitoring unit as claimed in any of claims 26 to 28 wherein the computer processing unit generates an output signal if the water content within the fluid supply is outside of a predetermined tolerance value.

30) A fluid monitoring unit as claimed in any of claims 26 to 29 wherein the computer processing unit generates an output signal if a density or mass of the particulate or debris content within the fluid supply is outside a predetermined tolerance value.

31 ) A fluid monitoring unit as claimed in any of claims 26 to 30 wherein the computer processing unit generates an output signal if the quality or purity of the chemical composition of the fluid supply is outside a predetermined tolerance value.

32) A hydrocarbon exploration and production installation, the installation comprising at least one supply conduit that provides a means for fluid communication between a fluid source and a fluid conduit, and a fluid monitoring as claimed in any of claims 17 to 31 , wherein the fluid monitoring unit is located within the supply conduit upstream of the fluid conduit.

33) A hydrocarbon exploration and production installation as claimed in claim 32 wherein the installation further comprises a pump located between the fluid source and the fluid monitoring unit.

34) A hydrocarbon exploration and production installation as claimed in either of claims 32 or 33 wherein the installation further comprises a shut off valve located between the fluid monitoring unit and the fluid conduit.

35) A hydrocarbon exploration and production installation as claimed in any of claims 32 to 34 wherein an output signal from the fluid monitoring unit is employed as a feedback signal to activate a shut down of the pump.

36) A hydrocarbon exploration and production installation as claimed in claim 34 wherein an output signal from the fluid monitoring is employed as a feedback signal to activate closure of the shut off valve.

37) A hydrocarbon exploration and production installation as claimed in any of claims 32 to 36 wherein the installation further comprises an operations control module connected to the fluid monitoring unit so as to provide a means for monitoring and recording output data from the fluid monitoring unit.