Study On Hydraulic Fracturing Technology On Ultra-deep Well In Central Junggar Basin

With the progress of oil and gas exploration technology,more and more ultra-deep and low permeability reservoirs have been explored,which is important to ensure the development of petroleum industry in China.Fracturing is the most aggressive stimulation means to develop ultra-deep and low permeability reservoir and have been increasingly paid attention.However,the success rate and effective rate of fracturing in ultra-deep well are very low.Faced with many difficulties to be overcomed:A poor reservoir property,high Young modulus and Poisson ratio lead to the high formation fracture pressure,dynamic fractures are narrow and sand fracturing is difficult,and high construction pressure which demand the fracturing equipment and string withstand high pressure.This paper aimed at experiment with the core of central Junggar basin by rock mechanics experiment.Combined with logging data,build the relationship between dynamic rock mechanical parameters and static rock mechanical parameters,and establish ultra-deep reservoir fracture pressure prediction model.This provide a basis for reducing the risk of construction and optimizing the technology of construction.Then optimizing the aggravating agent,thickener,crosslinking agent,breaker and temperature stabilizer of fracturing fluid and form a new fracturing fluid system,which can increase the hydrostatic pressure and reduce construction pressure.The density of fracturing fluid can reach 1.4~1.6g/cm~3.Simulate fracturing operation by numerical simulation software such as gohfer and stimplan to optimize the construction parameters and fracture parameters.Eventually reservoir reconstruction technology has been completed and this technology is going to guide fracturing operation on site.