Use of metal sillicides in hydrocarbon production and transportation

A method of removing buildup of asphaltene or waxy deposits in pipelines such as subsea pipelines uses metal silicides to generate heat and pressure inside the pipeline comprising injecting an organic slug comprising at least 10% metal silicide and hydrocarbon fluid and injecting an aqueous slug comprising water. The metal silicide reacts with the water to generate heat and pressure inside the pipeline to remove the deposits. Also described is a method of hydraulic fracturing which uses metal silicides to generate significant pressure inside a wellbore. The method comprises injecting a fracturing fluid and an aqueous or reacting fluid into the wellbore to react with the fracturing fluid. The fracturing fluid comprises metal silicide, which may be uncoated or coated, and hydrocarbon fluid. The reacting fluid comprises water or a solvent. Alternatively, there is also provided a method for purifying flowback water produced from a hydraulic fracturing process comprising adding metal silicide to the flowback water produced from a hydraulic fracturing process.