Search

To face the new challenges of production metering and back allocation, TOTAL is making an important effort to develop and test new approaches to improve its current production metering systems particularly for multiphase conditions. New technologies are tested through pilot applications within different subsidiaries worldwide. Thanks to these pilots, the suitability of various approaches to the needs of each asset can be analyzed and tested in detail. The SPE-149908 (M. Haouche 2012) paper presented a Virtual Flow Meter (VFM) field pilot in Qatar. The approach used on this VFM is the Data Validation and Reconciliation (DVR). The single Well model of the VFM is an assembly of three main units: Reservoir unit, Electrical Submersible Pump (ESP) unit and Production Tubing unit. The conclusion was that the VFM was catching-up the production trends of all the Wells of the pilot. However, the VFM results are not quantitatively comparable to the production measurements, especially when the VFM is running far away from the calibration period. A recommendation was to enhance the ESP model that controls mainly the information on the flow rate. The present paper describes a new method for modeling the ESP performances in the VFM. This method takes into account the impact of the Gas on the ESP performances. Results are presented for three operational cases to see the benefits of this method and where it is applicable. The ESP operational data have been considered for a long time period in order to get a representative range of operational conditions. Conclusions are made on the capabilities of the new method to assess the impact of Gas on the ESP operational performances.

The availability of reliable data is obviously a prerequisite to good production optimization. So far, many tools have been developed to increase the availability of data by using Smart Completions, Downhole Measurements and Remote control Sensors installed along the production chain. The progress in production models has also contributed to this improvement. Nevertheless, in term of reliability, the collected data are affected by uncertainties, which must be taken into account. The process of Data Validation and Reconciliation (DVR) considers all the relevant information (measures/ models) of the production plant as one integral set of parameters. Furthermore, the originality of DVR as compared to equivalent systems is the use of a statistical model to control uncertainties associated with each parameter, and calculating the resulting error propagation. As results and thanks to the information redundancy, DVR allows an automatic real-time correction of each parameter based on its allocated uncertainty. In this paper, we focused on a real time application with 16 Wells belonging to 3 offshore Platforms. The single-Well model is initially validated by using the Multiphase Flow Meter (MPFM) measurements. The global results analysis is discussed by comparing the online application outputs with production tests using MPFM, in terms of Oil flow-rate and Water Liquid Ratio (WLR). Also, the monitoring of each information is highlighted in order to detect a model deviation or instruments failure. Furthermore, the error distribution is used to identify the impact of any deviation occurring in the application. Conclusions are drawn on the performance of the virtual metering system in terms of online availability, results reliability and global consistency between data and results. The DVR application is considered as an operational monitoring tool thanks to alarms which are customized by operators, and as an analysis tool for investigation and diagnosis studies.