Circuitry Design For Extended Rotary Sidewall Coring Tool

With the acceleration of oilfield exploration and development process,the exploration reservoir becomes increasingly complicated and concealed.Meanwhile,the difficulties of exploration and development are also more and more complex.The collection of geological information for the most realistic and intuitive has gradually become essential means for oil reservoir geological experts to accurately evaluate.Directly from the strata of the core is the most intuitive first-hand information to understand,which is helpful to the analysis and identification of the reservoir.Currently cores for analysis can be obtained through three ways: drilling coring,explosion impact sidewall coring and rotary sidewall coring.Due to the complex construction of drilling coring,labor intensity,high cost and affect the drilling speed,the first way is not suitable for the whole area coring of all wells.The second way is the explosive impacted borehole coring that gets the core with small size and irregular shape.The structure of the core is destroyed during the impact process,which is not conducive to physical analysis and testing and can also not get the real porosity and permeability of the reservoir parameters,the explosion at the same time destroys the well wall.a lot of debris are left in the wellbore causing wellbore contamination.With its simple construction,low cost and core rules,rotary sidewall coring can not only do visual observation of rock oil,but also by the help of analytical instruments for lithology,electrical properties,physical properties and oil analysis,obtained porosity,permeability and other reservoir parameters.rotary sidewall coring is used widely,which is the largest potential coring way.The function of direct drive rotary sidewall coring tool is realized by designing the electronic circuit.The main work includes chip selection,hardware circuit design,CPLD programming and PCB design.The circuit includes power supply circuit,communication control circuit,main parameter measurement circuit,solenoid valve control circuit,motorcontrol circuit and motor power drive circuit.The power circuit realizes the power supply to the downhole tool.Communication control circuit realizes the communication between downhole tool and surface system.The main parameter measurement circuit realizes the acquisition of the downhole sensor signal.The solenoid valve control circuit realizes the acquisition of the state of the solenoid valve.The motor control circuit and motor power drive circuit realizes the control and drive of brushless DC motor.Based on the above work,the PCB board is made and the circuit has been tested.The electronic circuit meet the need of rotary sidewall coring tool.The designed circuit and the coring probe can be connected,the instrument can accomplish the task of rotary sidewall coring.