Monitoring of many upstream oil and gas production assets is challenging, due to factors such as the limited availability of suitably-qualified personnel and / or difficulty of access in, for example
Sensors are now in service on a full range of materials including carbon and cast carbon steel, P5/5 chrome, P9/9 chrome, 1% Cr (5130), duplex, P265GH (430-161), 1.4571 (316Ti), P295GH (17Mn4), monel, HR120, Inconel, Incoloy and hastelloy.
Watch a video about the benefits derived from deploying the Permasense ET210 system in the upstream sector:
The ET system is designed specifically to deliver a quality and frequency of measurements required for online corrosion or erosion monitoring and also to be extremely quick and easy to install in upstream environments. ET sensors measure wall thickness through external protective coatings - meaning that the external corrosion protection remains completely intact. ET sensors are affixed via integral magnets or a lightweight strap to equipment in a matter of minutes.
The WT sensor series is available in a marine variant - with a tip seal to reseal the external coating protection and duplex steel metal componentry. At most upstream operating temperatures, the WT sensors can be mounted onto clamps:
The Permasense system can be installed anywhere on FPSO topsides and below deck, utilising a cabled version of the sensors.
Sensors can be deployed on FPSO lines including: production, crude oil transfer, crude oil cooling, crude oil export, LP gas compression, HP gas compression, sea water, produced water, drains.
The waveguides isolate the sensor electronics from extreme pipework temperatures – on FPSOs these can reach 180-190 °C - and guide the ultrasonic signals to the pipe wall and back.
The systems can be configured to meet the demands of offshore facilities and their unique capabilities provide very significant benefits to users. Permasense has already supplied systems for offshore gas production platforms. Users have a more accurate, and real time, understanding of corrosion and erosion rates, and the risk to personnel in collecting data is eliminated, together with the cost of offshore visits.
The long-range system is already in service across the wellhead to processing facility feeder lines in a production field.
The Permasense system offers flexibility of monitoring locations for example on insulated lines.
At Europe's first LNG export facility sensors have been placed at multiple circumferential locations for each axial location. Piping varies from carbon steel with a 38mm thickness, to duplex of 25mm thickness, to SMO steel of 3mm thickness.The pipe diameters range from 8 to 36 inches, with operating temperatures of around 100°C (210°F).
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CASE STUDY - Statoil Hammerfest experience
A Permasense corrosion monitoring system at the Statoil Hammerfest LNG facility included over 40 sensors being installed. This facility is the world’s most northerly and Europe’s first LNG export facility, located on Melkøya island in Finnmark County, Norway.
The Permasense system has been put in place to assist with monitoring the thickness of pipeline walls to enable future detection of corrosion activity, and with reliable, continuous data help inform maintenance requirements and enhance reliable and safe operations. Key considerations in choosing the system were that it is non-intrusive, that it does not require maintenance, and that data is delivered to the desk, reducing personnel visits required to potentially dangerous process areas.
The sensors have been placed in circumferential rings, with sensors placed at multiple circumferential locations for each axial location. The piping varies from carbon steel with a 38mm thickness, to duplex of 25mm thickness, to SMO steel of 3mm thickness. The pipe diameters range from 8 to 36 inches. Generally these are operating at temperatures around 100°C.
At this facility extremes of ambient temperature are also experienced and it was important that the sensors could reliably operate in these harsh environments.
The facility has been constructed on Melkøya island, which is connected to land through an underwater tunnel.
Case Study - Offshore Production Platforms - Sand Erosion Monitoring
Produced fluid often includes significant and unpredictable sand content, posing an integrity risk through erosion of platform pipework and other fixed equipment. The rate of sand erosion depends on production rate, level of sand hold-up and particle size, but since hold-up and particle size vary unpredictably with time the rate of erosion is impossible to reliably predict.
Typically, the highest erosion rates will occur in areas of highest velocity or where the flow direction changes suddenly. In gas production platforms, this is usually
• directly after the choke, where the flow rate is increased;
• on the outside radius of bends;
• just downstream of bends, especially straight after the choke or downstream of blind Tees.
For a given level of sand hold-up, erosion rates increase dramatically as production rates are increased. This can cause the platform operator to have to limit production rates to minimise the integrity risk.
Installing Permasense wall thickness monitoring sensors across these high risk areas is an extremely cost-effective solution for monitoring sand erosion rates. Knowledge of sand erosion rates in real-time allows for safe maximisation of production rates.
A gas producer operating one of several wells on an unmanned platform at 250 mmscfd (2.5×105 MBTU per day) installed a Permasense system of ~30 sensors at locations downstream of the choke and downstream of the first bend - blind Tee - after the choke. This enabled continuous tracking of wall thickness in these areas, giving confidence to increase production on this well to 280 mmscfd (2.8×105 MBTU/day), a 12% increase, with confirmation that erosion rates did not increase. This gave a payback period on the Permasense system within several days of increasing the production rate.
Based on this success, this customer has now installed a similar Permasense solution, on-stream, on each of the wells on this platform and is extending the solution to other gas production platforms in the field, both unmanned and manned.