In November控制工程网版权所有, we discussed the special needs of making custody transfer measurements in large-scale applications where product characteristics are complex and dynamic. In this installment, two applications are highlighted where end users have addressed requirements to monitor multiple product variables simultaneously控制工程网版权所有, with reliability and precision.

　　EnCana has to monitor flows at strategic points throughout its enormous network. In some cases it may be at a collection point from a cluster

of satellite wells, or farther down stream at a major distribution point. The dynamic nature of its product mix requires agility and precision from instrumentation and control equipment. Source: Prosoft
　　Field application: EnCana
　　DPH Focus Engineering of CalgaryCONTROL ENGINEERING China版权所有, Alberta控制工程网版权所有, provides turnkey oil and gas plant automation and process control engineering. In the early 1990s, EnCana (Canada’s largest oil and gas company) approached DPH about improving production monitoring to improve management of its energy resources.
　　EnCana produces approximately 4.4 billion cubic feet of natural gas equivalent per day. More than 80% is natural gas and the balance is from in-situ recovery of bitumen through steam-assisted gravity drainage. EnCana has been a leader in development of this tar sands recovery technique, with much of that product sent to the U.S. for processing in its refineries there. EnCana produces oil from five Canadian sites and gas from nine major sites primarily in Canada but also in the U.S. Growing demand has pressed the company to increase production by 14% in 2007 over 2006 levels. The large geographical areas involved combined with a mix of products requires sophisticated control of operations and distribution.
　　EnCana and DPH started out by assessing the flow measurement techniques that were in use. EnCana was using mostly manual collection methods such as chart recorders for recording flow information and then compiling flow totals. As DPH investigated more sophistica