| Composite perforation and high energy gas fracturing is to put the priming system such as perforating bullet and propellant into underground oil and gas layer. The dynamic high pressure produced by its explosion combustion make the formation formed multiple fractures, and achieving the purpose of production. Composite perforation/fracturing process mechanism is complex and the theory is not sound. The influence factors are various, but the most difficult thing is the limit of high-temperature, high-pressure, high-impact, narrow space and other environmental conditions, so the access to information, conventional research methods and means is very difficult to get. This paper focuses on the key difficult problem of information acquisition in composite harsh environment to conduct research, aimed at building access to information platform of underground mechanism. It provides a data and information support of composite perforation, the design of the high-energy gas fracture and the stimulation of construction process optimization.This paper used a method of combining theoretical analysis and experimental verification, four mainly researches are as follows:(1) This paper studies signal characteristics of the downhole perforation and fracturing, the influence of special environment conditions on the testing system, structure design to resistant the bad environment, the analysis of pressure pipeline effect, variety of trigger modes, etc. We design and implement the annulus multi-parameter testing system and gun internal pressure test system.(2) We had more aspects of the research counter the complicated severe environment in downhole which is high temperature high pressure high impact and narrow space, the design of high pressure resistance based on the thick wall cylinder and the protection design and improvement of gun inside testing system. Using hopkinson bar impact testing device to conduct high impact test for different packaging materials and packaging mode chips. It provided an experimental and theoretical basis for the SoC encapsulation. We studied the changing mechanism of potting material strength characteristics along with temperature. We improved the high temperature performance of epoxy potting materials by using the method of adding inorganic filler. We made circuit module integral reinforcement potting improved by using the new technology of vacuum potting-pressure curing. This ensures the high strength and high impedance requirement of circuit module under high temperature environment. We have conducted the high temperature resistant and micro power design of the circuit by the research and analysis of the related chip high temperature performance.(3) We have put forward new ideas and methods of the dynamic calibration in the analog environment; established a calibration experiment system which is dedicated for simulating the temperature and pressure environment in the downhole; improved the sensor acceleration effect test system under pressure conditions; fixed a sensor temperature effect and acceleration effect and achieved the calibration curve and compensation formula. The calibration experiment system for simulating of the downhole temperature and pressure environment can simulate a well temperature(<150℃) and static pressure (<50mpa) with the depth of5000m underground. And it can simulate the dynamic pressure of the downhole perforation/fracturing. We conducted dynamic calibrations for testers by using a pressure test system whose three swings were measured and traced. Dynamic calibration experiments were conducted by using these systems, and the dynamic uncertainty of testing systems were studied and analyzed. All of these not only to ensure the measured accuracy of the petroleum downhole tester, but also the universal significance to improve the accuracy of the dynamic test instruments in harsh environments. It is an important academic innovation.(4) Some detailed analysis about typical experimental data for various types of downhole such as conventional perforation, built-in composite, coat type compound, deflagration fracturing, coalbed methane well composite perforation, etc. was conducted in this paper. We explore the high energy gas well fracturing mechanism, especially summarizes the influence mechanism between the high energy gas dynamic high voltage pulse waveform and crack form and length; represent the fracture behavior by using the dynamic pressure curve; discusses the favorable pressure waveform of fracturing effect; analyzes and studies the law of dynamic pressure measured curve. Moreover, we analyzed the important influence factors of composite perforation in cased well:perforation diameter, perforation density and propellant combustion characteristics, well intraocular pressure in liquid, perforation azimuth. And the mechanism about how these factors affecting composite perforation effect was studied. Finally, we put forward a optimization design method of "estimate-test-estimate-alter" which is based on P-t curve.This article research conclusion was applied on dozens of oilfield and enterprise in domestic such as Daqing oilfield, Liaohe oilfield, Changqing oilfield, Puguang gas field, Hancheng CBM field and so on. It provides acquisition method of key downhole real-time live information. The downhole multi-parameter testing system conducted a lot of tests for the existing main perforation/fracturing technology type. The acquisition of some data was the first at home and abroad. The information acquisition method and theory promotes the downhole perforation/fracturing mechanism research. It provides key information support for not only the optimization of the design parameters in perforation/fracturing construction technology and the increase effect of perforating/fracturing but also improvement of the exploitation of oil and gas layer rate and yield. |
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