DEVICE FOR TAKING SAMPLES OF FORMATION FLUID IN WELL Russian patent published in 1996 - IPC

FIELD: gas and oil producing industry. SUBSTANCE: device for taking samples of formation fluid in well is a structure built-up of two sampling units installed on both sides of control mechanism. Control mechanism is adjusted for certain pressure at preset depth of well where samples are to be taken. When device is lowered into well, fluid enters through special ports the control mechanism to built up pressure on plunger. Pressure rises as device moves downward, and at the preset depth of well, it reaches the critical value when it becomes equal to pressure at which pins are sheared. Coupling is ruptured (pins are sheared), plungers free the passage for sampled fluid to valve unit. Under the pressure of fluid, the valves open and fluid flows to under the separating piston in receiving chamber. Piston forces the ballast oil out of receiving chamber to ballast chamber through hydraulic resistor. When piston reaches the extreme position, pressures inside and outside of the device equalize, and valves of valve unit are closed under the action of springs. When device is being lifted, outside pressure decreases. Return spring of valve unit presses valve to its seat to prevent sample loss and fluid pressure in receiving chamber exerted on closing valve rises. When device is lifted to the surface, ballast chambers and control mechanism are screwed out. Receiving chambers with valve units are sent for investigation of fluid sample from well. EFFECT: higher efficiency. 4 dwg