With the drastic reduction of China's land and shallow sea oil and natural gas resources, offshore oil and gas field exploration has gradually developed into the deep sea of 1500-300 m. Traditional steel materials are no longer applicable, and fibre composite materials have become the most exploited in subsea oilfields. One of the good materials is widely used in all aspects of deep-sea oil field equipment, providing a reliable guarantee for the development of deep-sea oil and gas fields. Based on this research background, the paper discusses the characteristics of carbon fibre composite materials (light weight, high specific strength, high specific modulus, fatigue resistance, corrosion resistance, and small thermal expansion coefficient), and discusses its application in the field of subsea oilfields.

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With the gradual increase in the comprehensive utilization rate of industrial solid waste, the quality and safety of drilling solid waste recycling products have become increasingly prominent. This article starts with the hazards of drilling solid waste resourced products to the human body and the environment, adopts the method of hazard factor identification, constructs a qualitative and quantitative index system for the quality and safety evaluation of solid waste resourced products, and proposes corresponding evaluation procedures and countermeasures.

As a high-efficiency, low-cost, convenient and environmentally friendly sterilization technology, electrochemical disinfection has developed rapidly in recent years. Electrochemical sterilization is an environmentally friendly sterilization technology. The research progress of this technology in the recent 30 years in sterilization mechanism and electrode materials is summarized. The mechanism of electrochemical sterilization includes the chemical effects of active chlorine, active intermediates, copper or silver ions, and the physical effects of electric fields; the electrode materials used are titanium anode, carbon cathode, and anode. The article combined with electrochemical equipment in a thermal power plant cold open circulating cooling water treatment experiment. Experimental research found that under the conditions of current density of 120A/m2, residence time of 10s, and electrode spacing of 1.8cm, the bactericidal effect can reach 97%. Under certain experimental conditions and a certain period of time, the total number of heterogeneous bacteria in the circulating cooling water after treatment can be effectively inhibited.

Haynesville shale gas wells are operated over a wide range of back pressures, varying from 8000 psi or higher at early time to 1000 psi or lower at late time. Traditional Arps Decline Curve Analysis (DCA) presumes constant back pressure, and therefore over-predicts Estimated Ultimate Recovery (EUR) for Haynesville wells when applied at early time, prior to reaching line pressure. A new method has been developed to forecast well EUR earlier and more accurately by using pressure normalized rate instead of actual rate. In this method, the actual rate is normalized to the rate corresponding to a constant operating pressure. DCA methodology may then be applied to this normalized rate to forecast EUR. This new method yields consistent EUR predictions from much earlier time than traditional DCA methods, and converges to the same EUR as the traditional DCA method once constant flowing pressure is reached. Both field data and simulation results confirm the advantages of this method. The new method is practical to use and it reduces the uncertainty range of well performance predictions, thus providing better and earlier well performance comparisons, a quicker assessment of completion trial results, and more accurate booking of reserves and resources.