Study On Perforation Technology Of Hydraulic Blasting For Continuous Tubing

CT-employed (Coiled Tubing) hydrajet perforation technology can solve the oil-gas reservoirs’ stimulation problems effectively in Sichuan and Daqing where the reservoirs are low permeability, thin layers and large interlayer spacing. The water eroded tunnel which is formed by CT-employed hydrajet perforation causes almost no damage to the reservoir. What’s more, the quality of the tunnel directly affects the effect of the subsequent stimulation.In this paper, the measures including theoretical investigation, laboratory test analysis and numeric Simulation. First I started from Bernoulli’s principle, hydrajet cutting model and the micro-mechanism of hydrajet perforation to demonstrate that the hydrajet perforation does almost no damage to the reservoir.Then I did some research about the influencing factors of CT-employed hydrajet perforation consist of inlet pressure distribution and in-hole flow field of fixed speed perforation, Internal pressure distribution, the influence of perforating parameters to formation breakdown pressure and casing strength, etc. The main parameters of CT-employed hydrajet perforation (nozzle parameter, operation pressure) are calculated and the technological process, equipment, precautions are briefly discussed in the procedures section. I also proffer some original opinions about corrosion causes of hydraulic jetting tools and improving measures. A concept design about CT-employed hydrajet perforation of well-A was completed.Through this study, I have a further theoretical understanding of CT-employed hydrajet perforating technology and the process of concept design. I also summarized water jet tools’ corrosion reasons and improve measures. This paper laid a theoretical and practical foundation for the development of low permeability reservoirs.