Abstract

The Starcut low-gas three-phase meter configuration was developed to meet the specific needs of the Minas EOR development program. That is, a low cost three phase meter was needed which would provide the required accuracy for the high watercut, low gas fraction production conditions in the Minas field. This application was recognized as having general value throughout Texaco operations as well. Therefore a high priority project, funded by CPI and Texaco, was developed at Texaco EPTD to apply existing Starcut technology to this new application. The project was started in March, 1993. Six months later, the Starcut low-gas 3-phase meter arrived in Minas August 16, 1993 and was tested until September 16, 1993.

The original objectives of the Starcut Low-Gas 3-Phase Meter were portable installation at the well head, ability to report oil, water and gas fractions and flow rates for the range of 70-100% watercut, 500-15000 barrels of liquid per day, over gas fractions of up to 3% with instrument pressure drops not exceeding 40 psi. Based on encouraging data obtained at Texaco labs, the original objectives were expanded to include more ambitious gas handling of up to 20%. Also it was decided to see how far the Starcut technology could be pushed to meet other uses in the Minas area. For example, low pressure, high gas, slugging flow conditions were found at an existing well test station which was located more than one kilometer from the well heads. These operating conditions were briefly examined using the Starcut system. Portability was demonstrated by operation from a car electrical system and 2 hour relocation times between sites.

Preliminary results indicate successful operation of the Low-Gas Three Phase Meter on a low gas well 3D-86, however with some limitations. Potential for much greater gas fraction handling capabilities was also indicated on well 3D-74. However, high temperature operation damaged the teflon sensor cell early in the test program requiring excessive calibration efforts and prevented the test program's completion.

Based on the results and experiences described herein, Texaco and CPI determined those design changes required for the high temperature range (90° to 120° C), higher gas levels, long term effective use of the instrument, increased accuracy, reduced pressure drop, improved operator interaction and portability. These changes have been incorporated into a final version Low-Gas 3-phase meter for general use. The newly designed instrument is intended to be available for final testing in Minas in July, 1994.