Study On Quality Evaluation And Influencing Factors Of Dissolved Methane Concentration Data In Marine Bottom Water Obtained By In-Situ Monitoring

The research results at home and abroad have shown that,in addition to the marine area survey,in the partial exploration of the gas hydrate resources drilling target area screening and environmental monitoring of the development process,the in-situ methane test technology equipped with sensor equipment is more than that obtained by the conventional CTD method.With the characteristics of true,accurate,rapid and high accuracy,the measurement operation method is simpler,faster,and superior and feasible.It is an inevitable trend for the development of the detailed measurement technology of marine fluid geochemistry in the future.However,domestic and foreign literatures have so far not been able to provide such actual cases of underwater instrument testing and actual measurement data.Therefore,there are problems in the rationality of physical parameter settings and the quality of measured data that may occur in the testing process.However,it is only in theoretical assumptions and predictions,and lacks specific research and analysis,evaluation,and application guidance.These are the only ways that the seawater methane in-situ rapid test technology can be used for development and application.Based on this purpose,this paper aims at the in-situ methane sensor data obtained from long-term monitoring of bottom water in the Jiaozhou Bay waters,and under the conditions of gas sample specification input,the quality of measured data during the testing process of gas sensitive test systems and the impact of data changes.Factor research,this is the necessary and guaranteed condition for obtaining credible data results.The paper completed the following main tasks:(1)Based on the review of literature data and on the basis of the development and experimental application of seawater methane in-situ sensors,the working principle and characterization parameters of gas-sensitive probes based on electrochemical in-situ sensors were summarized.(2)To complete the 151-day monitoring of dissolved methane in marine bottom water in the Jiaozhou Bay sea area in-situ sensor,and to obtain monitoring data of in-situ dissolved methane concentration in the bottom water;(3)Through the comparison of actual measurement data and monitoring data,the changes of physical and chemical parameters of the sensor's sensitive probe performance,absorption of gas samples,and residual background are summarized,and the degree of influence on the test data,change laws,and geochemical characteristics are summarized.;(4)According to the influencing factors,design a simulation test and complete the sensor probe long-term monitoring test under the influence factors.According to the simulation test data analysis and research summary,the overall evaluation of the actual measurement data and the elimination of influencing factors and correction program method research proposals.