Objectives and problems to be solved:
The overall objective is to increase the effectiveness of hydro fracturing technology in the extraction of gas from tight reservoirs containing water-sensitive clays.
Phase 1 will investigate the scope for minimizing clay swelling effects and water block, for enhancement of flow-back and clean-up, and the use of special proppant size and coating to reduce and eliminate post frac proppant flow-back. It will also study the method of application e.g. the method of successful placement of large proppant in the fracture.
Phase 2 will then apply the results of fluid selection and large proppant fracturing procedure to a gas reservoir.
Description of work:
- Optimization of new chemicals, fluids additives, foaming agents etc., for tight gas conditions
- Modification of Tigre tester/core flushing test with different fluids on core material
- Laboratory test to identify the effectiveness of proppant size on post fracture flow back- New chemicals and downhole chemical delivery system
- Tool development to make e.g. perforations, explosives MECFRAC, slots/slits, trenches
- Theoretical study, followed by experimental work on large blocks.
- Carry out fracture treatments using the results of the fluid and large proppant research programs
- Carry out a production test after the hydraulic fracture treatment and analyse the data, including proppant flow-back. This work will be carried out under the supervision and responsibility of the participating oil companies, but the practical aspects will be executed by various service companies.
Expected results and exploitation plan:
- Definition of a non-damaging procedure for fracturing these type of tight gas reservoirs
- Definition of a procedure for large proppant fracturing these low permeability reservoirs
- Application/demonstration of the delivered results will help to develop a number of gas fields, e.g. in Germany and the Netherlands, but probably also in other European countries. Potential reserves to be developed are 200 billion m³
.- Presentation of intermediate and final results and start defining a commercial plan.
Optimum proppant size was determined from proppant flow back tests Laboratory work. Investigation of available completion tools on the market for proppant exclusion has been completed. Numerical modelling of drag forces and proppant flow back prediction has been completed using a numerical simulator, which models the flow along the fracturing including non-Darcy effects. Implementation of a fracturing treatment offshore The Netherlands has been completed using the findings of this project (laboratory results and numerical modelling). Quantification of the reservoir permeability damage due to the fracturing fluid residue has been progressed to the extent that a new base fluid has been identified. More work is required to arrive at a fully formulated novel frac fluid. Indications to improve the fracturing fluid systems applied in tight reservoirs. Reporting.
Funding SchemeCSC - Cost-sharing contracts
2514 HD Den Haag ('S-gravenhage)
AB32 6TQ Westhill (Aberdeenshire)
2280 AB Rijswijk Zh