Laboratory Experiment Study On Shallow Geological Hazards Identification

Deepwater drilling always experience shallow flow,shallow gas and gas hydrate and other geological hazards,which brought great difficulties during deep water drilling construction,and even cause catastrophic accidents.Therefore,it is necessary to identify the shallow geological hazard before drilling,and the existing identification and prediction methods can not meet the requirements of accurate identification.In this paper,a shallow geological hazard identification experiment is carried out indoor.And we carry out a method to predict shallow geological disaster,so that we can provide a scientific basis to ensure drilling safety.In order to study the method of shallow geological hazard identification,this paper simulates the shallow strata of the target block in the laboratory experiment,and studies the sound velocity characteristics of shallow gas and shallow flow.The longitudinal wave velocity of the normal strata and the shallow gas and shallow water flow is measured by the velocity measurement device.And this paper find out the law of change of the longitudinal velocity of the shallow gas and shallow flow with the pressure.The response model of acoustic parameters of shallow gas and shallow flow is established.According to the soil mechanics parameters of the target block and the experimental results,the acoustic velocity of the sediments of different soil parameters in the shallow strata of the target block is calculated and the actual measurement data of some blocks are compared with the inversion data.According to the formation mechanism of shallow geological hazards,the geological hazard and the distribution of shallow geological hazards in the target block,the concrete identification and forecasting is carried out according to the geologic disaster and the shallow geology.Then,we design a program to identify target block A well shallow gas,shallow flow,and carry out a risk assessment.