This paper describes a method of sand consolidation and channel repairing by using a Resin system, the system comprises of a resin (a mixture of elastomers UF, MF and a suitable plasticizer) and a hardener (a mixture of two mild Lewis Acids). The hardener controls curing time. The role of plasticizer is to impart flexibility and impact resistance to otherwise brittle natured UF-MF resin. Surface bonding between Sand and resin has been enhanced with a special additive, if required.
This paper also describes a methodology of placing a chemical casing during or after drilling a caving prone shale zone, strong enough to prevent sloughing of shale and withstands mechanical shocks during drilling, which would facilitate drilling with reduced mud weight and without reduction of hole size.
Experimental results on resin development and mechanical parameters of sand consolidation and Chemical casing of different mineralogy have been presented. The compressive strength of the consolidated sand and shale is found to be extremely high to withstand the overburden pressure and mechanical impacts during drilling. The designed application methodology is described in detail.
This system would be extremely economic as it can be applied directly after perforation if required, saving rig time and reducing completion cost compared to Gravel pack, liner placement and Screens, with the added advantage of no hole size reduction and better sand consolidation as compared to other methods. The developed chemical system is 1/3 the cost of epoxy resins, reported earlier for similar application and the components are environment friendly and easy to handle because of their water solubility.