API Publ 2566:2004 pdf download
API Publ 2566:2004 pdf download.State of the Art Multiphase Flow Metering.
The attractiveness of the new multiphase metering systems, operating unattended and without the need for phase separation, stemmed from their potential to avoid or overcome some of the above operational problems. Multiphase meters provide a system that can be installed subsea. In addition, these advantages can produce significant savings especially in offshore operations. The less bulky and lighter weight of multiphase meters was a major attraction for the installation offshore and therefore a significant influence in the evaluation of the technology, especially for operators in the North Sea (11-19, II- 22) and the Gulf of Mexico.
The oil industry has recognized the potential benefits of the new multiphase meters (II- 10 to 16). A systematic effort was undertaken in the 90’s by several North Sea operators to identify potential multiphase metering applications, reservoir engineering needs, and meter performances for a number of asset developments in North Sea (11-22). For the past 10 years, considerable effort has gone into developing multiphase meters that can measure gas, oil, and water flow rates at wellhead conditions (Il-i). These efforts have led to the development and marketing of several types of multiphase meters. In the past five years, the meter manufacturers and operators have jointly tested multiphase meters under a variety of field conditions to evaluate their performances. In the next sections of this paper, we shall look at the trends in installations of multiphase metering systems.
Wet gas metering is a more recent area of development in multiphase measurements. Wet gas metering covers a variety of measurements in production streams with high to very high gas volume fractions. There is a need for direct measurement of gas under these conditions in such applications as gas condensate and high GOR fields as well as many production operations where gas from separation systems may contain liquid (Ill-i). Furthermore, significant amount of gas will be produced in the future from remote and subsea fields where production, capital investment, and operating costs must be optimized. As an example, gas production from deep waters in the GOM (111-4) has increased in the last several years. Real time measurement of gas and liquid flow rates are critical in a subsea production system to improve well allocation, optimize reservoir production, and enhance flow assurance. In many of the deepwater reservoirs, the economic developments dictate that several fields be commingled together and processed at a central facility. In such cases, it is critical to be able to measure the produced gas at the wellhead in order to be able to allocate the oil and gas assets to partners in each reservoir (Xll-4). These trends have provided much support to the development of more robust and accurate wet gas metering systems.
Two major factors have contributed to the wider spread of the technology:
. Development of efficient compact separators (ll-28) has resulted in the
availability multiphase metering systems utilizing partial separation (off-line). In contrast to the in-line multiphase meters，which accept the fullstream,the off-line systems depend on the removal of most of the gasfrom the liquid flow stream. The temporary separated gas and liquidstreams are subjected to measurements before being recombined into theinitial full stream. These off-line multiphase metering systems are lesscomplex and still offer some, if not all， of the advantages of the in-linemultiphase measurement systems – i.e. real time measurement,shortertest time，and smaller size and weight relative to traditional gravityseparation vessels,but larger than multiphase meters.The developmentof these systems is discussed in more detail later in this report.
. The compact size of multiphase meters has also resulted in the
deployment of mobile systems. Mobile systems have enabled operators touse the multiphase metering technique in remote regions or in operationswhere a conventional well testing facility would not be available.Trailer-mounted multiphase meters have been used for well testing in fieldswhere wells are scattered over a large area (IV-10，V-13).In the past 3years the number of mobile systems have increased significantly.
