FORMATION TESTER Russian patent published in 1997 - IPC

FIELD: oil and gas industry. SUBSTANCE: this relates to devices for investigation of oil and gas wells during their drilling without lifting drill string in geology, geophysics, and mining industry. Formation tester has body with radial passages, hydraulic packer, hollow sampler with passages and partition which divides it into sample taking and additional chambers. Also provided are spring-loaded spool valve and spring-loaded bush installed in body for possible interaction with hollow sampler which has safety circulation valve. Sample taking chamber has partition with axial passage and is provided with floating piston, formation fluid inlet and outlet valves, solenoid valve, and two make electric contacts. Formation fluid outlet valve is connected with pusher of spring-loaded spool valve. Solenoid valve is located and fixed in sample taking chamber on upper end face of its partition coaxially with its axial passage. Floating piston is provided with tongue rigidly attached to it and pressure sensor. Hollow sampler is additionally provided with down-hole multiplicator pump. Working chamber of down-hole multiplicator pump is hydraulically connected through non-return valve and formation fluid outlet valve with under-piston zone of sample taking chamber and hole clearance. Hydraulic packer is made with sectional body and radial passages. Six passages converge in packer hollow which is made in wall of sectional body. Located in hollow is spring-loaded spool valve intended for connecting and isolating of under-packer, in-packer and above-packer spaces with tube space and hole clearance. Made between valve for inlet of working agent into system of passages of down-hole multiplicator pump and spring-loaded spool valve with pusher in side wall of additional chamber of hollow sampler is radial passage for inlet of working agent and distribution of pressure on valves adjacent to it. Discharge of used working agent of down-hole multiplicator pump and water solution from sample taking chamber into hole clearance is effected through radial passage in side wall of additional chamber of hollow sampler, radial passages of spring-loaded bush and sectional body of hydraulic packer during formation testing. This ensures increase of formation investigation period due to circulation of drilling fluid, allows for operational measurement of production rate, determination of formation permeability, phase permeability, inter-reservoir pressure, curve of pressure recovery in time. EFFECT: high efficiency. 4 dwg