Patent EA-027484-B1 (EA)
Title: Method for forming an extensive filtration channels system in a formation and performing geophysical research therein, and a device for implementation thereof
Inventor: GALAJ MIKHAIL IVANOVICH
IPC: E21B43/11
Filed: 2014-07-28
Abstract: The invention is related to the oil- and gas-producing industry and can be used in completion of productive formations by forming a system of extensive filtration channels, oil and gas wells recovery and creation of perforation holes in the casing string. The essence of the inventions: in accordance with the method, a turnable and axially movable bottomhole assembly (BHA) is mounted on the tubing string, the BHA comprising a guide shoe with a curved channel for movement of a high-pressure hose (HPH) with at least one nose-piece therethrough, and a hole forming assembly (HFA) for making holes in the casing string (CS) while providing alignment of outlet openings of the shoe and HFA and a permanent axial distance between their outlet openings; the BHA is descended to a preset depth and installed in the CS by means of a pipe anchor; a geophysical instrument determining spatial position of the BHA outlet channels is descended; on the basis of the instrument readings, BHA is turned to a position at which the HFA outlet opening is disposed in the preset azimuthal direction; after returning of the geophysical instrument to the well mouth, the CS HFA is opened and the first hole is formed; BHA is turned to position HFA outlet opening in the next preset azimuthal direction at the same level without moving the tubing string along the well bore and without performing any additional descending/ascending operations; the next hole in the CS is formed while controlling the cutting tool position; on completion of forming holes in CS, without performing any descending/ascending operations, BHA is transferred to a position where the outlet opening of the guide shoe curved channel is disposed opposite to the first hole drilled in the CS; HPH with an attached water-jet nose-piece is descended in the tubing string on a long-length flush-joint pipe, and then HPH is advanced along the guide shoe curved channel into the first CS hole with the water jet nose-piece position control followed by forming the first extensive filtration channel by means of pressure of working fluid supplied to the water-jet nose-piece through the long-length flush-joint pipe and HPH from the well mouth; HPH is lifted slightly to a position where the water-jet nose-piece is disposed higher than the guide shoe; HPH is turned to a position where the outlet channel of the guide shoe is disposed opposite to the next hole drilled in the CS, and the next filtration channel is formed; on completion of forming the extensive filtration channels system at the same level, the long-length flush-joint pipe and HPH are lifted to the well mouth, and HPH is provided, instead of the water-jet nose-piece, with a reactive nose-piece equipped with a geophysical instrument for determining spatial position of the filtration channel, its length and geophysical properties of the formation within the boundaries of the filtration channel length; the long-length flush-joint pipe and HPH with the reactive nose-piece and the geophysical instrument are lowered into the filtration channel providing HPH movement along the channel and monitoring direction and length of the filtration channel and geophysical properties of the formation; control of direction and length of the entire system of filtration channels and geophysical properties of the formation rocks is performed. The device for implementing the above-described method of forming an extensive filtration channels system in the formation and performing geophysical research therein comprises the following components mounted from top downward on the tubing string: a joining assembly of a geophysical instrument, a collector unit controlled from the well mouth, rotatable and movable axially BHA including a guide shoe and HFA linked rigidly to each other, and a monitoring and control unit and BHA turning and axial movement mechanism connected electrically, via the collector unit, to a control station at the well mouth. The guide shoe has a curved channel for HPH moving therein with provision of the possibility for HPH going to the annular space, HPH having replaceable nose-pieces: a water-jet nose-piece that provides forming in the productive formation a system of extensive filtration channels arranged at the same level and directed radially relative to the borehole axis, or a reactive nose-piece equipped with a geophysical instrument determining length and spatial location of the filtration channel and geophysical properties of the formation. Nose-pieces movement along filtration channels is provided by working fluid supplied from the well mouth under pressure. The geophysical instrument mounted on the joining assembly provides determining the initial direction of outlet channels of the guide and HFA of the descended BHA. The device includes also a pipe anchor and components that control position of the cutting tool and position of the water-jet nose-piece at the inlet of a drilled hole, the information being transmitted to the well