ACCELERATED BROWNFIELD RE-DEVELOPMENT II: MAJOR MIDDLE EASTERN OPERATOR
By Dr Michael Gibson
This second section of the three updated Well Consultancy articles shows how www.wellideas.co.uk is flexible enough to manage and deliver bespoke well consultancy programs worldwide for a variety of Operators. In this article, www.wellideas.co.uk well consultancy describes how it managed and delivered a customized / bespoke well brownfield re-production programme for a major Middle Eastern Operator following its success with a major Operator in Europe.
In this spectacular country, one major oilfield was selected in the Desert Area of the Country due to a combination of declining oil production and increasing water production. The field was labelled as a “Gas Oil Gravity” Field – which is a very old misnomer – from “way back” many, many decades ago.
Wellideas assembled experts for well consultancy in their fields from the U.S.A, the UK and from throughout Arabia. This multi-national group of expert personnel were charged by both the Operator and The Ministry of Petroleum of the inherent country with the aims of a) determining how remaining reserves might be accessed using new technology and b) what the capital expenditure was likely to be in utilising this new technology and c) the risks involved.
The well consultancy team took an “area by area” approach to examining and understanding the field, beginning with its history, original production rates, understanding of the reservoir (which is essentially a Limestone Reservoir with severe fractures) and how the reservoir was developed over the decades. Well consultancy detailed study over time in terms of oil production, gas production and water production allowed personnel to see at what rate water production was rising whilst oil production was falling, and to note the key oil production fall-off rates and rise in water production rates, along with any other anomalies. In many cases, oil production had been shut-off some time ago and it therefore had to be investigated whether a full workover or re-drilling might prove beneficial as opposed to any possible intervention.
The options open to the Operator in Terms of Workover were a) Removing the Existing Production Tubing and Re-completing the well; b) Side-tracking existing wells through either slim-hole drilling assemblies or Coiled Tubing; c) Acidizing certain reservoir matrices, d) Fracking certain matrices, e) Water-shut-off re certain reservoir matrices, f) Fracking certain matrices, g) Water-shut-off, h) Lowering surface back-pressure for example, i) the use of velocity strings.
With oil and gas currently at such high prices, several operators are beginning to assess the viability of “Brownfield Re-Development”, literally to see if there are any attractive ways in which remaining reserves can be produced.
Typically, over time, oil production decreases whilst water production increases. The schematic below shows the “production” behaviour of this fascinating Middle Eastern Reservoir, which has been labelled a GOGD or “Gas Oil Gravity Development Reservoir. The key to such a “Brownfield Re-Development Study” is to understand the reservoirs and their production performance over time, and to see if there’s any “low hanging fruit” left so that it may be produced economically.
This requires specialist teams, and investment, but there have been good results in many “Brownfield Areas” over time.
This Brownfield Re-Development Project was carried out the wonderful country of Oman, the UK, and the U.S.A, with extensive data being made to all delegates, including literally everything from seismic through to production data and experts who had advanced knowledge of modern technology. The information, after having been gathered and collected in Oman, was transported to Houston where a full team of geologists, new technology experts and “lateral thinkers” were utilised over a period of several weeks. The findings were then presented to the Teams in Oman. Key to the findings were using modern technologies.
Such modern technologies were as follows: –
- Use of New Seismic
- Specialist Production Data Computer Programs for Analysis / Modelling
- Analysis of Original Well Completion Performance
- “Look Ahead” Performance Modelling
- Slim-Hole / Coiled Tubing Drilling
- Modern Water Shut-Off Chemicals
- Velocity Tubes
- How to reduce Surface Back Pressure
- Downhole Technologies as required.
The whole field was cross-sectionalised and examined in the same way.
They were then compiled electronically per the Operator’s requirements, and all work and data was available electronically 24/7 – although there were many “interesting” discussions per the Houston results.
Finally, at the end of the 6-month contracted period, it was agreed by the Operator and the ministry of Petroleum that the findings should be studied diligently, and this is what indeed happened. It was believed that 10’s of billion barrels of hydrocarbons remained in situ – it was really a question as to how to “produce the remaining reserves”.
In summary, this was an excellent example of creative thinking in terms of a bespoke programme structure in terms of the potential for Brownfield Redevelopment, exceeding, by far the Operator’s expectations.
Who is Dr Michael T. Gibson?
Dr Michael T. Gibson has 40 years in the Oilfield, working initially as a Drilling Engineer when he studied Mechanical and Offshore Engineering at Bachelor’s, Diploma and Master’s, Degree Level at Robert Gordon’s in Aberdeen under the expert tutelage of Professor Blythe McNaughton. He then went on to take a PHD over an 8-year period whilst working offshore as a Drilling Supervisor.
He began teaching / lecturing full-time 15 years ago in many parts of the world for Oil Companies, Drilling Contractors and Universities and has written the vast bulk of Wellideas’ material, ranging from Manuals, Pocket Handbooks, PowerPoints and Videos for the Classroom and Zoom Meetings, through to E-Learning Modules for distance learning.