METHOD OF DIFFERENTIAL PRESSURE FEEDING OF GAS OR GAS-LIQUID MIXTURE BY MEANS OF PASS-THROUGH LIQUID PISTON Russian patent published in 2007 - IPC F04B19/06 

FIELD: oil and gas producing industry.

SUBSTANCE: invention can be used at drilling, completing and operating of oil and gas wells for compression and delivery of gas or gas-liquid mixtures. Proposed method of compression of gas or gas-liquid mixture is based on differential delivery of gas or gas-liquid mixture by means of pass-through liquid piston moved in additional compression chamber by movement of two or more three-dimensional displacers of different capacity and building different pressure in working chamber. One of displacers is arranged in part of working chamber separated from compression chamber by means of bridge. Separated part communicates with compression chamber by means of channel furnished with controllable valve. During part of suction stroke (or complete suction stroke as in some cases), part of working chamber separated by bridge is isolated from compression chamber by controllable valve. When valve is closed, suction by displacer found in isolated part of working chamber takes place from liquid line. It provides getting of portion of liquid required for compensation of irrevocable losses in liquid piston or getting of required gas-liquid proportion. During suction stroke, when controllable valve is open, suction of liquid is provided from compression chamber. All displacers provided reverse stroke of pass-through liquid piston. Simultaneously filling of additional compression chamber with gas or gas-liquid mixture takes placer. Time of "isolation" is determined by algorithm of operation of controllable valve depending of required amount of back-up liquid added into pass-through liquid piston at each cycle. At delivery stroke, forcing out of liquid from working chamber into compression chamber is provided successively by all displacer, starting from displacer of maximum capacity but minimum pressure. Each following displacer features lesser capacity as compared with previous one, but it develops higher pressure.

EFFECT: increased volumetric efficiency, possibility of control of gas-liquid ratio of delivered medium.

1 dwg