Perforating device and method for hydraulic fracture physical simulation experiment

Abstract

The invention discloses a perforating device and a perforating method for a hydraulic fracture physical simulation experiment. The device comprises a die for pouring cement, a steel pipe which is arranged in the die and is provided with penetrating holes in the side wall, and solid sticks fixedly inserted into the penetrating holes of the steel pipe, wherein a solvent for dissolving the solid sticks can be injected into the steel pipe. The method comprises the steps of drilling the penetrating holes in the side wall of the steel pipe, processing the solid sticks which are matched with the holes in the steel pipe in size and can be dissolved, and fixedly inserting the solid sticks into the holes of the steel pipe; fixing the steel pipe and the solid sticks into the die, and pouring a space in the die except the inner cavity of the steel pipe with cement; after the solidification and maintenance of the poured cement are ended, pouring the solvent capable of dissolving the solid sticks into the steel pipe so as to dissolve the solid sticks, and forming pores and ducts which are used for simulating perforating. The device and the method can be used for simulating a perforating state in an actual oil-gas well in a large-scale cement-poured rock sample and have the characteristics of simple structure, convenience in operation and high applicability.

Description

technical field [0001] The invention relates to the technical field of hydraulic fracturing simulation experiments in the development of oil and gas fields, in particular to a perforation device and method for physical simulation experiments of hydraulic fracturing. Background technique [0002] Hydraulic fracturing is a promising oil and gas well stimulation measure and one of the important technologies used to develop low-grade oil and gas resources. It requires the use of a large amount of water mixed with chemicals to inject shale formations for hydraulic fracturing to release natural gas. In order to explore the technical process of improving hydraulic fracturing, it is necessary to conduct hydraulic fracturing simulation experiments in the laboratory to study the mechanism of crack initiation and expansion, and then develop related technological methods. Among them, large-scale physical simulation experiments are carried out in the laboratory, that is, the sample size...

AI Technical Summary

Problems solved by technology

In the current physical simulation experiments, there are generally two methods for simulating perforation in oil and gas wells: the first method is to use perforating guns to perforate the poured cement rock samples, but due to the physical The experimental samples cannot resist the impact force generated by the perforating bullets used in actual operations, and the samples are easily broken after perforation, making it impossible to carry out the next experiment

Another method is to roll the high-strength packaging hard shell paper into the form of perforation tunnel when pouring cement rock samples, insert and fix it on the steel pipe with side wall holes, and then prefabricate the two together on the cement However, especially in the process of pouring experimental rock samples, due to the large sample size, a large amount of cement needs to be used, and the weight of the cement deforms the hard shell paper, even in some places completely The shape of the perforation tunnel is lost; in addition, since the hard shell paper still exists outside the perforation tunnel after pouring, the crack needs to penetrate the paper roll during the experiment, and there is a huge difference in the mechanical properties of the paper roll and rock, which is equivalent to artificial The addition of an interface effect affects the initiation and expansion of fractures, which is not conducive to the observation of experimental phenomena and the study of fracturing expansion theory

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