Abstract: The present invention relates to an apparatus for inspecting and monitoring flexible collection and production lines in real time, rendering possible constant tracking of the condition of the internal structures of a flexible riser, specifically of the tensile armor thereof. The device may be provided at any point along the riser ensuring the establishment of an area of physical and visual contact directly over the surface of the tensile armor of the riser for the installation of equipment for analysis, which area permits further accesses without destroying the sealing of the chamber there formed.

Abstract: A tool for subsea installation and testing of wellhead modules such as Xmas trees and similar equipment, from a ship using a ship crane. The tool includes a subsea unit that includes a connector for releasable connection to subsea wellhead modules or equipment, means for positioning and means for testing, and a connector for electric power and electric and/or optical control.

Abstract: A fluid treatment system comprises a fluid treatment module having a fluid inlet and first and second fluid outlets. A pump is provided to establish a first pressure differential between the fluid inlet and one of the first and second fluid outlets of the fluid treatment module, and an eductor is provided to establish a second pressure differential between the fluid inlet and the other of the first and second fluid outlets of the fluid treatment module. The pump is adapted to deliver a motive fluid to the eductor.

Abstract: A system, apparatus, and method are provided for monitoring a subsea flow device such as a subsea flowline. The apparatus generally includes a thermoelectric device that is adapted to generate electric power from a thermal potential between the subsea flow device and the surrounding seawater. A sensor that is powered by the thermoelectric device is adapted to monitor one or more characteristics of the flow device, such as temperature or strain, and provide a radiation output that is indicative of the characteristic.

Abstract: A telemetry apparatus and method for communicating data from a down-hole location through a borehole to the surface is described including a light source, an optical fiber being placed along the length of the wellbore and receiving light from the light source, a transducer located such as to produce a force field (e.g. a magnetic field) across the optical fiber and its protective hull without mechanical penetration of the hull at the down-hole location, one or more sensors for measuring down-hole conditions and/or parameters, a controller to provide a modulated signal to the magnetic field generator, said modulated signal being under operating conditions representative of measurements by the one or more sensors, and an optical detector adapted to detect changes in the light intensity or polarization of light passing through the fiber.

Abstract: A method, device, and system for determining whether liquid enters a subsea system includes a flow line having an inside bore capable of carrying producing fluids from a subsea wellhead to a floating production storage and offloading vessel (FPSO). An annulus is defined between an innermost sheath that surrounds the inside bore and an outermost sheath at an exterior of the flow line. The device further includes a housing element disposed within the annulus and in hydraulic communication with the annulus; a sensor element disposed at a predetermined location within the housing element; and data acquisition equipment capable of: determining environmental characteristics of the annulus based on measurements made by the sensor element, and determining at least one of the presence, location, and rate of collection of liquids in the subsea system based on the environmental characteristics of the annulus.

Abstract: An example downhole tool configured for conveyance in a wellbore extending into a subterranean formation comprises a first fluid communicator configured to allow drilling fluid communication with an annulus between the downhole tool and the wellbore, a second fluid communicator configured to direct formation fluid to the annulus, and a formation testing device disposed deeper in the wellbore relative to the first fluid communicator and configured to pump formation fluid from the formation to the second fluid communicator. At least one of the first and second fluid communicators comprises a jet pump.

Abstract: A sampling device is for subsea fluids. The sampling device comprises: a sample container including a first chamber and a second chamber, the first and second chambers being isolated by a movable separating body, a first pressure sensing device for sensing the pressure in the first chamber of the container, and a second pressure sensing device for sensing the pressure in the second chamber of the container. The sampling device further comprises a pressure compensating device, the pressure compensating device being adapted to compensate for pressure changes in the first chamber of the container by regulating the pressure in the second chamber of the container and thereby moving the separating body. A method is for subsea fluid sampling using a sampling device.

Abstract: A temperature compensated accumulator and method for use thereof downhole in a well. The accumulator may include a housing with separate bulkhead and piston assemblies. Thus, one assembly may include a hydraulic fluid chamber separated from a gas precharge pressure chamber by a piston and the other assembly may include an ambient pressure chamber separated from an atmospheric chamber by another piston. Additionally a pressure relief and check valve assembly may be located at a pressure relief chamber between the other assembly sections. Thus, venting to or from the gas precharge pressure chamber may take place upon exposure to a predetermined decreased or elevated temperature so as to maintain a substantially constant precharge level for the accumulator, for example, in spite of dramatic changes in downhole temperatures.

Abstract: A method of operating a system for handling an influx of gas into a marine riser during the drilling of a well bore includes the steps of operating a first riser closure apparatus to close the riser at a first point above a flow spool provided in the riser, there being a riser gas handling line extending from the riser at the flow spool to a riser gas handling manifold, operating a second riser closure apparatus to close the riser at a second point below the flow spool, pumping fluid into an inlet line which extends into the riser at a point above the second point but below the flow spool, and operating a choke provided in the riser gas handling manifold to maintain the pressure in the inlet line or the riser at a substantially constant pressure.

Abstract: A system and method for channeling fluids from underwater to the surface. Including a channel system for channeling the fluids from an oil leak through the channel system starting from an underwater pipe leak to a containment reservoir at a sea surface. In one aspect, the channel system is made up of interchange parts, where some are flexible, attachable, and/or can influence the flow of the fluids inside the channel system.

Abstract: Biphenylmono- and polysulphonic acids and salts thereof, fluorenemono- and polysulphonic acids and salts thereof as well as p-terphenylmono- and polysulphonic acids and salts thereof may be used successfully as tracers for surveying, monitoring and/or measuring movements of aqueous fluids in aqueous and/or non-aqueous media. Said substances are especially suited for surveying or monitoring movements of fluids in oil wells or reservoirs as well as for fluid movements in hydrothermal reservoirs.

Abstract: Method and subsea sensors display system configured to display data about a blowout preventer (BOP) stack. The subsea sensors display system includes a display panel having plural universal subsea displays, each universal subsea display being configured to display a value measured by a sensor attached to the BOP stack; and a J-box electrically connected to the display panel and configured to provide electrical power to the display panel and to receive data from the display panel. The electrical power is provided from a pod provided on the BOP stack or from a battery when the pod is not available or from a remote operated vehicle (ROV) when connected to the display panel.

Abstract: The present invention is directed to methods and systems for obtaining log data on a cased wellbore concurrently with wellbore cleanout operations. In some such embodiments, a combination of at least one cleaning means and at least one logging tool are integrated or otherwise affixed to a common workstring, such that both wellbore cleanout and logging operations can be accomplished without having to remove the workstring from the well between such operations. In some such embodiments, the one or more logging tool(s) transmit information about the cased wellbore to the surface wirelessly. In some or other such embodiments, such information is transmitted via cable, in real-time or in batch mode. In some or still other such embodiments, such information is stored in memory and accessed subsequent to the workstring being extracted from the wellbore.

Abstract: Adapters for inclusion on the lower end of a completion/work-over riser includes a flow loop in fluid communication with a production flow loop hub and a production bore to facilitate testing and calibration of a subsea multi-phase flow meter during completion operations. The flow loop can be in fluid communication with one or more flow loop isolation valves, one or more production bore isolation valves, one or more annulus bore isolation valves, or one or more cross-over valves. In addition, a pressure/temperature sensor can also be included in the adapter. The adapters disclosed herein permit production fluid to flow through the subsea multi-phase flow meter while the riser is still attached to the subsea Christmas tree and before production operations have begun.

Abstract: The present invention relates to an apparatus for inspecting and monitoring flexible collection and production lines in real time, rendering possible constant tracking of the condition of the internal structures of a flexible riser, specifically of the tensile armour thereof. The device may be provided at any point along the riser ensuring the establishment of an area of physical and visual contact directly over the surface of the tensile armour of the riser for the installation of equipment for analysis, which area permits further accesses without destroying the sealing of the chamber there formed.

Abstract: Methods and systems to characterize a fluid in a reservoir to determine if the fluid is in one of equilibrium or non-equilibrium in terms of one of gravity, solvency power, entropy effect or some combination thereof. The method includes acquiring tool data at each depth for each fluid sample of at least two fluid samples wherein each fluid sample is at a different depth and communicating the tool data to a processor. Determining formation properties of each fluid sample to obtain formation property data and determining fluid properties for each fluid sample to obtain fluid property data. Selecting a mathematical model based on one of gravity, solvency power or entropy, in view of a fluid property, using one of tool data, formation property data, fluid property data, known fluid reservoir data or some combination thereof, to predict if the fluid is in an equilibrium distribution or a non-equilibrium distribution.

Abstract: A subsea test tree control system provides operational control and power to subsea test tree equipment located within a subsea riser without an in riser umbilical to supply additional power to the subsea test tree control system. The subsea test tree control system includes a subsea horizontal subsea tree landed on a subsea wellhead, and a subsea control module communicatively coupled to the horizontal subsea tree. A subsea test tree stack is landed through the riser in the horizontal subsea tree. A subsea control module communication line extends through the horizontal subsea tree to terminate at a bore of the horizontal subsea tree proximate to the tubing hanger, and a riser string communication line communicatively couples to the subsea control module communication line to provide operational power and control the subsea test tree stack. Intervention workover control system umbilicals may bypass the subsea control module and directly connect to the subsea control module communication line.

Abstract: A structural health monitoring system for a marine composite riser string is provided. Each riser pipe section includes a cylindrical form having an axis and also a carbon epoxy matrix. A sensor is associated with (e.g., embedded in) and substantially circumscribes the riser pipe section. The sensor includes a PolyVinyliDene Fluoride laminate and electrodes (e.g., conductive silver ink coating) so that the sensor generates electricity at the electrodes responsive to mechanical stresses and strains of the riser section, including vibrations. The system can also include a data acquisition system and digital signal analyzer to analyze signals responsive to the generated electricity at the electrodes of sensors and to provide health monitoring and damage detection for the marine riser pipe string, including impact damage and fatigue crack initiation.

Abstract: A system and methodology facilitates utilization of a valve and a cutter both of which may be used in a subsea test tree. The valve comprises a ball element pivotably mounted in a housing and having an exterior surface and a passageway sized to receive a conveyance therethrough. The cutter also is located in the housing but at a position spaced from the ball element. The cutter is oriented for selective severing of the conveyance. Additionally, a seal system is positioned to act against a surface of the ball element.

Abstract: A hydraulic accumulator assembly in which a hydraulic accumulator is associated with at least one responsive unit, which is responsive to the weight of the accumulator to provide an indication dependent on the weight of the accumulator. The accumulator is in an underwater fluid extraction well facility.

Abstract: A system for monitoring a subsea structure is presented. The system includes a sensor disposed on or about one or more tubular components of the subsea structure, where the one or more tubular components of the subsea structure include a riser, a flow-line, and a subsea umbilical. Moreover, the system includes a controller operatively coupled to the one or more tubular components of the subsea structure and configured to detect an anomaly in the one or more tubular components of the subsea structure. A method for monitoring the subsea structure is also presented.

Abstract: A method of servicing a wellbore within a subterranean formation comprising providing a drill string disposed within the wellbore having one or more tubulars associated therewith and forming one or more annuli around the drill string; placing an insulating packer fluid comprising an aqueous base fluid and a viscosifying agent into at least one of the one or more annuli surrounding the drill string; and performing a drill stem test while the insulating packer fluid is in place. A method of servicing a wellbore within a subterranean formation comprising placing an insulating packer fluid in an annular space between a tubular and a marine riser extending from a surface vessel or platform and a subsea wellhead, wherein the insulating packer fluid comprising an aqueous base fluid and a viscosifying agent and has a thermal conductivity of from about 0.008 BTU/(hr·ft·F) to about 0.245 BTU/(hr·ft·F).

Abstract: A method of pressure testing a lower marine riser package includes forming an inflatable packer having exposed slats and an inflatable packer element. The packer is positioned within the lower marine riser package above the cap seal with the exposed slats above the packer element. The packer is inflated and fluid pressure is then applied to test the integrity of the cap seal. The packer may be inverted, then positioned below the BOP/riser connection, the packer inflated, and pressure increased above the inflated packer element to test the fluid integrity of the BOP/riser connection.

Abstract: A casing hanger seal assembly is lowered into a pocket between a casing hanger and a wellhead housing while in a run-in position. The seal assembly has a metal-to-metal upper seal ring and an elastomeric and metal lower seal ring carried by and below the upper seal ring. The upper and lower seal rings are movable from a run-in position to a set position sealing between the sidewalls of the casing hanger and the wellhead housing by applying a downward force. The downward force required to move the lower seal ring to the set position is less than the downward force required to move the upper seal ring to the set position. A downward force applied to the upper seal ring after the lower seal ring has landed in the pocket transfers to the lower seal ring to cause the lower seal ring to move to the set position before the upper seal ring moves to the set position.

Abstract: A permanent subsea sampling and analysis system is integrated into a replaceable equipment module for a choke valve of a subsea production well. The analysis system is self-contained, and separates a sample into liquid fractions consisting of crude oil, condensate and produced water and then measures the salinity of the water as well as the volumetric ratio between the liquid fractions all in the same sampling container.

Abstract: A system, method and device may be used to monitor fluid levels in a drill pipe in borehole. The system includes an electromagnetic (EM) generator to generate a traveling wave of electromagnetic energy to propagate along a linear path through the drill pipe towards a surface of the fluid, a detector to detect a portion of the electromagnetic wave reflected from the surface of the fluid and propagated through the drill pipe towards the detector, a processor to analyze detected signals to determine a level of the surface of the fluid. In an embodiment, the system includes a pump controller to control the operation of a pump located in the wellbore or at the mudline based on the fluid surface level.

Abstract: A system for monitoring a subsea well is presented. The system includes the subsea well, where the subsea well includes a production tube, an annulus A co-axial to the production tube and positioned exterior to the production tube, an annulus B co-axial to the annulus A and positioned exterior to the annulus A, and a casing wall disposed between the annulus A and annulus B. Furthermore, the system includes a first sensor disposed on or about the production tube, the annulus A, the casing wall, or combinations thereof and configured to measure a first parameter. The system also includes a controller coupled to the subsea well and configured to analyze the first parameter measured by the first sensor and detect an anomaly in one or more components of the subsea well. Methods and non-transitory computer readable medium configured to perform the method for monitoring a subsea well are also presented.

Abstract: Systems, computer readable medium, program code, and methods for monitoring and managing a plurality of marine riser assets are provided. An example of a system includes a computer and a computer readable medium containing a program code of instructions that when executed by the computer, cause the computer to perform operations for tracking the subsea deployment and retrieval of each of a plurality of riser joints. The operations can include receiving riser joint identification data from a riser joint identification indicator connected to the respective riser joint during the operational deployment thereof, and identifying the respective riser joint being operationally deployed to thereby track the deployment thereof. The operations can also include receiving riser joint identification data from the riser identification indicator of the respective riser joint during retrieval thereof, and identifying the respective one or more riser joints being retrieved to thereby track the retrieval thereof.

Abstract: Method is directed to determining a fluid influx profile and near-wellbore area parameters in multi-layered reservoirs. A bottomhole pressure in a wellbore is measured. After operation of the wellbore at a constant production rate, the production rate is changed. A bottomhole pressure is measured together with a fluid influx temperature for each productive layer. Graphs of the fluid influx temperature measured as a function of time and of a derivative of this temperature with respect to a logarithm of a time passed after the production rate is changed as a function of time are plotted. Relative production rates and skin factors of the productive layers are calculated based on these graphs.

Abstract: There is disclosed a method of monitoring a subsea installation comprising: providing data storage means in a subsea control module and storing data resulting from the monitoring of equipment of the installation in the storage means.

Abstract: Methods and systems for detecting subsea cement returns, leaks in subsea cement, leaks in blowout preventer operating systems or other equipment or conduits, or the presence of sweep or spacer media subsea or at the surface, include mixing an indicator, such as sodium fluorescein, with a quantity of cement or other medium, the indicator being insulated from contact with the subsea environment. The medium and indicator can be provided into a subsea wellbore, and upon contact of a portion of the medium with the subsea environment, the indicator can become detectable. Exposing the subsea environment proximate to the wellbore to a detector, such as an ultraviolet light source, enables detection of the indicator, and thereby, detection of the medium, which can indicate a cement return or leak of operating fluids in a subsea blowout preventer system.

Abstract: A plug assembly and method for pressure testing a shaft having a generally cylindrical member with a deformable outer surface comprised of alternating soft and rigid ribs and a central void for reception of a sealing component having a sealable central bore, a tubular adapter capable of releasable attachment to a drill pipe and releasably engaged to the cylindrical member, a plurality of ports about the circumference of the member for upward flow of fluid through the member and a receptacle in the member for placement of the sealing component for fixed attachment inside the member for creating a seal for testing pressure. The sealing component may use a ball valve to regulate flow and the cylindrical member may have rigid sections implanted between soft sections during manufacture to facilitate sealing upon pressurization.

Abstract: Method for determination of a fluid influx profile and near-wellbore area parameters comprises measuring a first bottomhole pressure and after operating a well at a constant production rate changing the production rate and measuring a second bottomhole pressure. A wellbore fluid temperature over an upper boundary of a lowest productive layer and wellbore fluid temperatures above and below other productive layers are measured and relative production rates and skin factors of the productive layers are calculated from measured wellbore fluid temperatures and measured first and second bottomhole pressures.

Abstract: A subsea drilling, production or processing actuation system comprising a variable speed electric motor (10) adapted to be supplied with a current, a reversible hydraulic pump (8, 28) driven by the motor, a hydraulic piston assembly (92, 101, 111, 121, 131) connected to the pump and comprising a first chamber (2), a second chamber (3) and a piston (4) separating the first and second chambers and configured to actuate a valve (91) in a subsea system, a fluid reservoir (14) connected to the pump and the hydraulic piston assembly, the pump, hydraulic piston assembly and reservoir connected in a substantially closed hydraulic system, and a pressure compensator (13, 65) configured to normalize pressure differences between outside the hydraulic system and inside the hydraulic system.

Abstract: A distributed function control module adapted for use in a modular blowout preventer (BOP) stack for use subsea comprises a housing, adapted to be manipulated by a remotely operated vehicle (ROV) with a stab portion adapted to be received into a BOP stack control module receiver. Control electronics, adapted to control a predetermined function with respect to the BOP stack, are disposed within the housing and connected to one or more controllable devices by a wet mateable connector interface.

Abstract: An embodiment of a method for limiting the probability of failure on demand of a subsea test tree (“SSTT”) includes the steps of providing a safety shut-in system for actuating a safety valve of the SSTT, the safety shut-in system including a surface control station positioned above a water surface connected via an umbilical to a subsea control system positioned below the water surface to actuate the safety valve; and diagnostically testing the safety shut-in system without actuating the safety valve.

Abstract: A running tool sets and pressure tests a bridging hanger and a packoff in a single trip. The running tool has a stem, an inner body, and a piston. The inner body is connected to the stem so that rotation of the stem relative to the inner body will cause the stem to move longitudinally. The piston is connected to the stem so that the stem and piston rotate and move longitudinally in unison. A piston engagement element is housed in the inner body and is adapted to engage the piston when the bridging hanger is set to prevent premature setting of the packoff. The piston engagement element can be disengaged once the bridging hanger is set, thereby allowing the piston to set the packoff.

Abstract: A component of the hydrocarbon well system and a first supply line to the component can be isolated from other components of the hydrocarbon well system. The component and the first supply line can be pressurized to a test pressure with a test fluid. Then, a pressure and a temperature of the test fluid in the component that was pressurized can be measured over a period of time. The pressure and the temperature that were measured can be analyzed and a pressure integrity of the component can be determined based on the analysis.

Abstract: A hybrid-tieback seal assembly and methods for tying a well back to the surface or subsea well head are disclosed. A method to tie a well back to the surface or subsea well head comprises running a hybrid-tieback seal assembly into a wellbore, the hybrid-tieback seal assembly comprising one or more anchoring bodies, one or more packer seal assemblies; and a device for creating a pressure differential in a tieback string, wherein the tieback string is coupled to the hybrid-tieback seal assembly. The method further comprises landing a casing hanger in a well head, increasing pressure in the tieback string, setting the anchoring bodies and one or more packer seal assemblies within at least one of a previously installed liner hanger system and a host casing above a previously installed hanger system, and testing the hybrid-tieback seal assembly down an annulus between the host casing and the tieback string.

Abstract: A method of enabling communication between components of a hydrocarbon extraction plant, the plant having an underwater hydrocarbon extraction installation including at least one hydrocarbon extraction well with an associated tree, comprises providing a plurality of RF communication means at respective components of the installation.

Abstract: An embodiment of a method of deploying a cable into a wellbore penetrating a subterranean formation comprises providing a cable, wherein the cable comprises at least one insulated conductor, at least one armor wire layer surrounding the insulated conductor, a polymeric material disposed in interstitial spaces formed between armor wires forming the at least one armor wire layer, and interstitial spaces formed between the at least one armor wire layer and insulated conductor, the polymeric material forming a continuously bonded layer which separates and encapsulates the armor wires forming the at least one armor wire layer, and whereby the polymeric material is extended to form a smooth polymeric jacket around the at least one armor wire layer, introducing the cable into a wellbore and performing at least one operation in the wellbore utilizing the cable.

Abstract: A wear bushing having a lead impression block is landed axially above a casing hanger and actuated to test an elevation of lock ring grooves formed in a wellhead. Then, drilling operations are performed through the wear bushing. The wear bushing includes a first tubular member having an axis and a second tubular member coaxial with the first tubular member. The second tubular member moves down to actuate a lead impression assembly to measure an elevation within the wellhead with the lead impression block. After the drilling operations are completed, the deformed lead impression block is retrieved along with the wear bushing.

Abstract: A non-invasive wireless communication system for monitoring parameters existing within the casing annuli of a subsea hydrocarbon production system. The subsea hydrocarbon production system includes a wellhead housing mounted at the upper end of a well bore and a number of concentric well casings extending from the wellhead housing through the well bore, and the casing annuli are formed between successive ones of the wellhead housing and the well casings The monitoring system comprises an interrogation package which is adapted to wirelessly transmit and receive NFM and/or inductive signals and at least one sensing package which is located in one of the casing annuli and is adapted to wirelessly receive the signals from and transmit response signals to the interrogation package.

Abstract: Methods, systems, and program product for monitoring and managing a plurality of marine riser assets are provided. An example of a method includes tracking the subsea deployment and retrieval of each of a plurality of riser joints. This can include deploying the plurality of riser joints from a vessel to form an operationally deployed marine riser string, reading riser joint identification data from a riser joint identification indicator connected to the respective riser joint during the operational deployment thereof, and identifying the respective riser joint being operationally deployed to thereby track the deployment thereof. The method can also include retrieving one or more of the operationally deployed riser joints, reading riser joint identification data from the riser identification indicator of the respective riser joint during retrieval thereof, identifying the respective one or more riser joints being retrieved to thereby track the retrieval thereof.

Abstract: A tool for subsea installation and testing of wellhead modules such as Xmas trees and similar equipment, from a ship using a ship crane. The tool includes a subsea unit that includes a connector for releasable connection to subsea wellhead modules or equipment, means for positioning and means for testing, and a connector for electric power and electric and/or optical control.

Abstract: There is provided a high power shear laser module, which can be readily included in a blowout preventer stack. The shear laser module as the capability of delivering high power laser energy to a tubular within a blowout preventer cavity, cutting the tubular and thus reducing the likelihood that the tubular will inhibit the ability of the blowout preventer to seal off a well.

Abstract: The present invention relates to a method for performing well operations from a floating installation comprising a high pressure riser (8) connected to the floating installation through a tension system, and where the riser comprises a housing (18) with an internal diameter larger than an internal diameter of the riser and connected at the top of the riser, where it for performing operations is made an assembly (15) comprising a desired numbers of modules for use in a specific operation, the modules are assembled at the installation, then positioned in the housing and the operation is performed through the assembly.

Abstract: A method of drilling a subsea wellbore includes drilling the wellbore by injecting drilling fluid through a tubular string extending into the wellbore from an offshore drilling unit (ODU) and rotating a drill bit disposed on a bottom of the tubular string. The method further includes, while drilling the wellbore: mixing lifting fluid with drilling returns at a flow rate proportionate to a flow rate of the drilling fluid, thereby forming a return mixture. The lifting fluid has a density substantially less than a density of the drilling fluid. The return mixture has a density substantially less than the drilling fluid density. The method further includes, while drilling the wellbore: measuring a flow rate of the returns or the return mixture; and comparing the measured flow rate to the drilling fluid flow rate to ensure control of a formation being drilled.

Abstract: A well comprising a borehole and wellhead apparatus, and a communication box at or proximate to the wellhead apparatus, the well comprising a plurality of sensors coupled to wireless transmitters which are adapted to transmit information from the sensors to the communication box; the sensors comprising at least one pressure sensor;and the well comprising a first memory device spaced apart from the communication box, the first memory device configured to store information from the sensors, wherein the communication box comprises a receiver adapted to receive signals from the transmitters, and at least one of a transmission device and a second memory device to transmit and/or store data received from the transmitters. The communication box is typically highly shock resistant (above 50 Gs for at least 5 ms, all axes) and so provides, together with other optional features, a system to monitor a well, especially before, during or after an emergency situation.