Research On Pyrolysis Process Of Surface Sand Ocean In Oil And Gas Field Based On Terahertz Technology

Characterizing the oil-bearing characteristics of shallow sand samples is of great significance to the petroleum geological exploration of desert reservoirs.Due to the low content of organic matter in the sand samples,the current geological extraction techniques used to determine the oil-bearing characteristics of shallow sands in oilfields are very limited.In this paper,terahertz time-domain spectroscopy,thermogravimetric analysis,infrared spectroscopy and other testing methods are used to systematically study the pyrolysis process of surface sand samples in oil and gas fields.The main research contents and results obtained are as follows:(1)This paper systematically summarizes the sample selection principle and sample preparation method of the surface sand samples used in the experiment,develops the terahertz time domain spectrum technology which can be applied to the shallow sand oil-bearing geological structure,improves the corresponding experimental data analysis and processing method,and provides a new idea and method for the oil and gas exploration and development in the desert area.(2)The terahertz time-domain spectra of sand samples at different temperatures were measured,and the influence of temperature on terahertz wave absorbance of pyrolysis products was studied.It was found that the pyrolysis process of sand samples can be divided into three stages: from room temperature to 300 ?,there is no obvious change in terahertz response during this stage;from 300 ?-700 ?,the decomposition of organics begins,and the attenuation coefficient of organics absorbing terahertz waveguide decreases From 700 ? to 1000 ?,the unit attenuation coefficient of terahertz wave tends to increase,because the absorption rate of oxide is higher than that of carbonate.(3)The thermal terahertz analysis method(TTA)was developed,combined with thermal gravimetric analysis and x-ray diffraction and other auxiliary methods,and the terahertz time-domain spectral measurement method was used to systematically study the pyrolysis process of sand samples.As a result,shallow sand samples were found in During the pyrolysis process from 300? to 700?,the change rate of the terahertz parameter is 20.4%,which is much higher than the 2.3% mass change rate in thermogravimetric analysis.The results show that the terahertz time-domain spectroscopy is easier to trace organic substances.Generate a response,identify the turning point between organic decomposition and mineral reaction,and then reveal oil-bearing structures and determine the pyrolysis products of shallow ground sand samples.