Techbits: Well and Reservoir Surveillance/Management in a High Oil Price World
Authors: JPT staff _ 
Published: February 2015

H.E.Y.B. Pehin Dato Yahya Bakar, Minister of Energy in the Brunei Prime Minister's Office, and Grahaeme Henderson, Managing Director, Brunei Shell Petroleum Co. Sdn. Bhd., set the stage for the SPE Applied Technology Workshop (ATW) on "Well and Reservoir Surveillance/Management in a $60/bbl Oil Price World." The ATW was held in Bandar Seri Begawan, Brunei, in March and was attended by 59 participants, representing 30 different organizations from 10 countries.
Helping operators to achieve the right balance between short-term production gains and long-term development interests was the objective of the comprehensive technical agenda. Case studies and practical applications were presented in the following sessions: Well and Reservoir Surveillance/Management in Field Development Planning, Well and Reservoir Surveillance/Management, Case Studies/Lessons Learned, Field Operations and Organization, and New Technologies. There was also a break-out session and a poster session.

Increasing Value in Brownfields
The value of integrated full-field reviews was emphasized during ATW discussion. It was pointed out that proper data gathering and quality of the data play a critical part in the review process. And, in the case of production sharing contracts, maintaining continuity from operator to operator is of prime importance. A wide range of recovery factors were presented, and it was suggested to use analogs to assess realistic recovery factors.

Reservoir-Monitoring Issues
In a high-oil-price environment, many well/reservoir surveillance activities can be seen as costly to operators. During this session, discussion from the standpoint of overcoming the legacy of a low-cost mindset included production of heavy oil and emulsions from subsea developments. It was pointed out that subsea production almost always represents a high operating cost. Particular challenges are pipeline sharing and the associated tariff/production allocation, sand/emulsion production (specifically, the emulsion problem is a complicated one because the physics of conventional multiphase meters is not valid, and therefore, these are unreliable). Other techniques, such as the use of flow and nodal analysis, are not entirely satisfactory because proper testing and metering are still required to support the model. The need for accurate metering of emulsion flow for subsea production is significant.

Surveillance in the Minas Field
Because of the mature status of the field, the surveillance and management approach has moved from a fieldwide to a more-detailed reservoir approach in order to be effective. The Minas field is the largest waterflood field in southeast Asia, producing at ≈98% water cut with a current recovery factor exceeding 50%. Production is 100,000 BOPD, and the associated water production is ≈5 million B/D. A policy of zero discharge has been implemented in the field since 1997.
It was shown how a predictive model is used together with validation from actual field data for reservoir and well management. Pressure measurements are taken twice a month in 50 dedicated observation wells, and production log tests are used for production allocations. Microgravity, x-well tomography, and geochemical fingerprinting are techniques now being implemented in this field.