The best way to tackle unwanted water
production is to shut it off downhole
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Excess water production can present challenges for oilfield operators, in how to control the problem to ensure the economic viability of their assets. DOSAS offers extensive expertise and solutions to water shut off, to examine the severity of the water production problem, and to understand the best solutions available to address these excess water issues, for the highest chance of treatment success.
When the well is complete, the job isn’t over. The challenge of keeping the oil and gas flowing now becomes paramount. Often the problem comes from the produced water. Our focus is to optimise our customers’ capital and operating expenditures to help them bring oil to the market with the highest profitability.
Data Analysis, Engineered Approach and Treatment Design
We support our customers for water shut off or conformance controls a selection of engineered technologies suited to specific well or reservoir conditions and economic considerations.
The specific water production mechanism has a very strong influence on the effectiveness of water shut off treatments and will determine the best approach for either chemical or mechanical solutions, or a combination of both. Therefore, thorough data analysis is essential to identify the source of water production is recommended. Once the mechanism is known, the appropriate chemical and mechanical treatment, or a combination, can be designed to achieve the best results. Our treatment for water control problem is designed through two primary categories:
Our Treatment Design
Data Acquisition
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In-depth information gathering and analysis to allow DOSAS technical team to conduct a full and proper engineering investigation, into the source water mechanism, thus allowing for identification of the most appropriate water shut off chemical solution.
- CBL, corrosion images from sonic imaging tool logs and completion schematics
- Reservoir imaging from acoustic tools
- Production pressures, particularly annulus pressures for studying wellbore stability
- Production Logs
- G&G data – 4D seismic and/or Analysis of G&G data and static models
- Well test analysis of production data or injection data
- Simulation and history matching, calibrating with other log data available
Chemical Evaluation, Test and Analysis
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Once the mechanism is known, appropriate chemical and/or mechanical solutions, formulation recommendations and treatment placement programmes, can be designed to achieve the best results based on Data Acquisition step.
- Method and required rheological properties of identified water shut off solution
- Mixing procedures for preparing chemical solution on site
- Optimum placement rates and placement sequence
- Guidance for injectivity testing
- Laboratory testing for confirmation of fluid stability, compatibilities and suitability for reservoir
Methodology for Water Control
Key analytical steps include from the beginning of a study may include:
- Define project objectives: reducing water cut, increasing oil production, or both;
- History of production and well performance analysis, completion configuration through reservoir zones;
- Consider wellbore stability for original cementing job, and identify potential causes of caverns, channelling, poor isolation and which may have encouraged production of undesired fluids;
- Wellbore isolation reviews;
- Review of sub-surface geological features and production history matching in sub-surface models to explore water movement through the reservoir;
- Once the mechanism is known, the appropriate chemical and mechanical treatment, or a combination, can be designed to achieve the best results.