METHOD OF BIT LOAD CONTROL DURING LATERAL DRILLING Russian patent published in 2014 - IPC E21B44/00 

FIELD: oil and gas industry.

SUBSTANCE: following equipment is installed preliminary: a) uncontrolled acoustic rejection filter in injection line in order to suppress interfering noises in wash liquid which are generated by drill pump; b) controlled acoustic rejection filter - rotational velocity sensor for hydroturbine motor shaft in order to carry out amplitude modulation of total sound, sound generated by rotor blades at hydroturbine motor shaft and sound generated by bit blows against rock to wash liquid filling drill-rod string; c) hydrophone with measurement tools between gooseneck in-built into swivel and drill hose. Turbine motor with bit at butt-end of drill-rod string is landed to the well with subsequent stop at distance of 10-20 metres from the bottom in order to measure rotational velocity of turbine motor shaft under no-load conditions. Drill pump is switched on to deliver wash liquid through drill-rod string to turbine motor for the purpose of rotor blades rotation. At that rotation of rotor blades generates sound in wash liquid. Then receipt is made by hydrophone from wash liquid by modulated controlled acoustic rejection filter - rotational velocity sensor for turbine motor shaft against noise amplitude proportional to rotational frequency of hydroturbine motor under no-load conditions in the band of suppressed interfering noise generated by drill pump, uncontrolled acoustic rejection filter. At that measurement devices convert processed audio information about rotational velocity of hydroturbine motor under no-load conditions in order to plot actual full-load characteristic by shifting plant characteristic in order to select optimal bit load at actual load characteristic of hydroturbine motor less friction of drill-rod string against walls of the horizontal well at minimum energy of sound propagated in the drill-rod string in wash liquid for this oil-reservoir horizon according to the work order specified by geologists. Then by means of set of discreet point actual load characteristic is plotted against simultaneous data - bit load and rotational frequency of hydroturbine motor shaft under no-load conditions before its stoppage, for example, at five tons. Then lateral drilling is made in optimal bit load mode shifted from plant load characteristic specified in the work order. In case of deviation of lateral drilling from the optimal mode demonstrating increase of sound energy from two sources bit load is regulated by change of load to a lesser or bigger value according to actual load characteristic of hydroturbine motor considering minimum energy of sound propagated in wash liquid from two sound sources - sound generated by turbine blades and sound generated by bit teeth blows to wash liquid filling the drill-rod string.

EFFECT: development of method for bit load regulation during lateral drilling against actual load characteristic of hydroturbine motor plotted against simultaneous data received in drilling process about rotational velocity and bit load.

6 dwg