This is a Joint Industry Project (JIP). Two tasks were set for the project:
1) Develop a comprehensive understanding of the nature and extent of the gas migration problem. A survey form was prepared, interviews with cementing experts are taking place, and a database of relevant information is being developed;
2) Conduct screening studies of existing remedial solutions.
Fluids of 1 cP and higher viscosity are commercially available, and the sponsors will pick three of them for screening. The second group of fluids to be evaluated will be 0.5 cP and lower systems involving polymers dissolved in light hydrocarbons. Westport will develop an ethane and propane based system for testing. A bundle of capillary tubes of different diameters will be used to screen the pumpability of the different fluids through simulated fractures.
Westport has experienced problems with placing enough of its low viscosity polymer plugging system into the test microfractures. The commercial higher viscosity systems are delivering more plugging agent than the low viscosity formulations. Westport will therefore begin testing higher viscosity polymer systems and taking advantage of the fact that the polymer system has zero set time (it is activated by pressure drop).