Field Experience With LACT Units Equipped With P.D. Meters

Lease automatic custody transfer (LACT) can be accomplished by the use of positive displacement meters and standard open-type prover systems to the satisfaction of producer, pipeline and regulatory bodies. Over 2,500,000 bbl of oil have been sold by this method. Meter factor vs cumulative meter registration graphs should be used to check meter performance, wear rate and proper proving interval. A check meter in series with the sales meter is recommended as an aid to elimination of major errors in the measurement. Large errors can occur on some oils if group temperature compensators and ASTM, Table 7, are used when ruling oil at high temperature. Samplers are reliable as far as BS and W determination is concerned but may not adequately represent the true API gravity if the sample is stored for extended periods of time. In one field operation, P D meter LACT has enabled the operator to gain an additional $100 per day by improving oil characteristics. Introduction During the last few years, the oil production departments of various oil companies have devised and built a number of installations to sell oil to pipeline companies by various metering devices. The advantages of the devices or LACT units, as they have been termed, have been pointed out by previous observers. The strong trend toward unitization of several leases into operating entities as well as rapidly increasing steel and labor costs have contributed to the rapid acceptance of the LACT method. While the producing companies pioneered the development of most LACT units, the various pipeline companies have given valuable assistance. At the present stage of development, LACT unit designs are beginning to crystalize and a number of manufacturers are now marketing complete systems. During the research and development phase, the economic advantages of LACT were not always evident to the producer or the pipeline; however, currently it is apparent that both parties are benefiting. For example, my company is now operating five LACT units which are handling 10,000 BOPD or over 30 per cent of our daily crude runs. Approximately fifty tank batteries have been salvaged out.