Study On Small Caliber Diamond Drilling Micro Foam Drilling Fluid And Dynamic Characteristics

The engineering geological conditions along the Sichuan-Tibet Railway are extremely complex,featuring high cold permafrost,fissure development,and large changes in topography and landforms.Drilling holes,collapses,and other problems are likely to occur during the geological exploration drilling process.Traditional irrigation fluid drilling system is difficult to solve the above problems to adapt to geological conditions.The paper focused on the investigation of the small-diameter diamond drilling of the Sichuan-Tibet Railway.An attempt was made to study a micro-foam rinsing fluid system that can be applied to the small-diameter diamond drilling of the geological survey of the Sichuan-Tibet Railway.In order to solve the problem of complex formations restricting the rapid drilling of small diameter diamond drilling.As a new type of rinsing liquid system,the micro-foam rinsing liquid has many advantages such as low solid content,good lubricating properties,good rheological properties,good drop-loss resistance,and high core rate.As a new type of rinsing liquid system,the micro-foam rinsing liquid has many advantages such as low solid content,good lubricating properties,good rheological properties,good drop-loss resistance,and high core rate.The micro-foam rinsing liquid has the above-mentioned characteristics,and effectively solves the problem of leakage,shrinkage,and boring of small-diameter diamond drilling under the complicated engineering geological conditions of the Sichuan-Tibet Railway.In the research of the performance of the micro-bubble rinsing liquid system,most of them are concentrated on the test and analysis under the static conditions in the room,and there is little research on the performance of the micro-foam rinsing liquid under dynamic cycling conditions.The dynamic characteristics of the micro-bubble rinsing fluid is mainly to understand the rheological properties of the micro-bubble rinsing fluid when it flows through the pores.It is of great value for the in-depth study of the micro-bubble rinsing fluid system.Therefore,the development and dynamic characteristics of micro-foam rinsing fluids that meet the requirements for small-diameter diamond drilling are studied.Focusing on research objectives,the work carried out in this paper and the results achieved mainly include the following:(1)Formulations were developed.In combination with the requirements of the Sichuan-Tibetan Railway survey on the performance of flushing fluids for small-diameter diamond drilling under complex conditions,Considering the performance parameters of the half-life,Orthogonal experiment was used to optimize the components of the micro-bubble rinsing liquid system,and the optimal formula of the micro-foam rinsing liquid system was obtained.(2)Performance testing and evaluation of formulations.Under static conditions,the resulting micro-foam rinse formulation was evaluated for its half-life,foaming capacity,rheological properties,and anti-contamination capabilities.The rheological mode of the micro-bubble rinsing liquid is a power law mode,and its overall performance is good.In addition,the micro-foam rinsing liquid prepared according to the recipe with low-speed stirring has a larger foaming amount.The results show that the formulation can still be foamed in large amounts under low-speed stirring conditions,and the equipment at the drilling site can be equipped with a micro-foam rinse solution.(3)Design and construction of dynamic characteristics test equipment.According to the characteristics of dynamic circulation of the micro-bubble flushing fluid in the borehole,a dynamic performance test bench for the flushing fluid in the room was designed and built.The test bench consists of four main parts,namely power control system,fluid control system,test system and foam preparation instrument.The test bench can effectively reduce the actual flow of the rinsing fluid in the borehole and accurately measure the performance parameters of the rinsing fluid under dynamic conditions,achieving the purpose of design.(4)Dynamic characteristics study.The built-up device was used to simulate the intra-hole circulation of the flushing liquid,and the performance of the micro-bubble flushing liquid under dynamic cycling conditions was tested and compared with the performance under static conditions.The built-up device was used to simulate the intra-hole circulation of the flushing liquid,and the performance of the micro-bubble flushing liquid under dynamic cycling conditions was tested and compared with the performance under static conditions.The results showed that the micro-foam washing fluid system showed good rheological properties,and showed some differences with rheological properties under static conditions.The rheological mode of the micro-foamed fluid under dynamic and static conditions is a power law mode,which shows the stability of the flushing fluid system.As the circulating pressure increases,the density,viscosity,and shear force of the micro-foam rinse increase.In the dynamic and static conditions,the system evaluated the micro-foam washing system.The test results showed that the formula had good rheological properties,reduced filtration loss,and wall plugging,which made it difficult to adapt to the small-diameter diamond drilling fluid.Complex stratum problems provide new ideas and have certain use value.The micro-foam rinsing liquid developed in this paper has good performance and can be applied to small-diameter diamond drilling under the complex geological conditions of the Sichuan-Tibet Railway.The designed test device can accurately test the performance parameters of the rinsing fluid under dynamic conditions,providing equipment support for in-depth study of rinsing fluid performance.The study of microbubble flushing fluid system has certain engineering value and practical significance for promoting the development of small-diameter diamond drilling technology.