To have a holistic view is important when designing a system that is easy to operate, complies to all relevant standards/ specifications and is cost effective. Analytic have both the knowledge and experience to select the optimal components to design and deliver a complete measurement system for FLNG’s and FSRU’s that is “fit for purpose”.
Regardless of looking at an FSRU or a FLNG, the measurement system consists of 4 main packages:
1. The feed or export gas flow and online quality measurement system
2. The LNG sampling and online quality measurement system
3. The metering supervisory
4. Laboratory analysis
Analytic have designed a flexible system that can be scaled to meet both global and customer specific standards and requirements.
A measurement system of high quality is important not only for reducing risks with allocation of profits and costs but also for building trust in the reported numbers and for minimizing the operational cost. To achieve this It is important to start with a thorough look at the contractual obligations between the seller and buyer of the gas/ LNG when prior to designing the system and selecting which measurement to be performed in a laboratory and which should be done online.
LNG sampling and online analysis
This system normally consists of a GIIGNL and ISO ISO8943 compliant gas sampling system and a gas chromatograph to measure the LNG quality. In addition, additional analysers may be connected to measure mercury, O2, sulphurs etc.
The important consideration for this part is the design of the LNG vaporizer. After the LNG is taken off the process line, it will be gasified. If this is not done properly, all measurements will be affected giving measurement results of poor quality.
Feed and export gas measurement
Analytic AS recommends to use two high quality ultrasonic meters in series for measuring the gas flow together with a gas chromatograph. This gives the possibility to reduce the required upstream and downstream pipe requirements. Below is a picture of a standard configuration.
The supervisory is the key interface towards all the analysers. It computes the relevant results according to specified standards, log data over the lifetime of the system, provides the service portal etc. It is designed to be easy to operate both remotely and locally and Analytic can perform diagnostics from our offices if required by the customer.
Based on the contractual obligations to analyse quality parameters, a choice must be taken on what to measure online or in a laboratory. With Analytic’s experience with designing on site laboratories, a complete laboratory with operational procedures should be included in the complete measurement package.
For more information contact Bård Elvik or Ulf Kommedal - contact information