In the tight gas formations the perforation channel can be created by means of abrasive action. If possible to implement, such a method would leave clean cut hole in the liner without sharp edges and perforation tunnel in the formation free of crushed zone. The main advantage of sand jetting perforation lays in the cleaner and larger perforation channel. Perforations created with sand jetting technique usually display reduced near wellbore friction during hydraulic fracturing operations.
The preparations for sand jetting perforation operation in deep wells require proper selection of the carrier fluid. In deep horizontal wells sand laden slurry has to travel through small diameter coiled tubing increasing the injection pressure at the pump. In order to lower pump pressure at the required treatment flow rates the sand is suspended in highly pseudoplastic fluid. The sand suspension in large suction lines and friction reduction in smaller coiled tubing (CT) are the main parameters required to complete the operation. The selection of proper carrier fluid maintaining both parameters at the bottom hole temperature is crucial to the job success.
This paper will discuss the testing of fluid systems from the perspective of the sand suspension and friction reduction capabilities along with the discussion of basic properties and parameters of the selected system. The findings from the tests will be verified by the actual sand jetting perforation operation on the offshore deep tight gas well.