A well completion method

Abstract

The method pertains to the oil and gas industry and can be used in the development of producing formations. A producing string ( 6 ) together with a sealing device ( 7 ) are lowered into a well ( 1 ) and the well ( 1 ) is divided into an upper cavity ( 8 ) and a lower cavity ( 9 ) with the aid of said sealing device ( 7 ) to establish a hydraulic connection between the well opening and the upper cavity and between the lower cavity and the producing formation, respectively. The installation of equipment ( 10 ) and a check valve is carried out stepwise. A washer fluid ( 4 ) is replaced by a washer fluid ( 15 ). The equipment ( 10 ) is passed through the sealing device ( 7 ) and the hydraulic connection between the well opening, the lower cavity and the producing formation is re-established along the annular channel. The well ( 1 ) is deepened using the equipment ( 10 ) until an inflow of formation fluids occurs, the differential pressure in the hydraulic system “well opening—producing formation” being adjusted using the check valve and a blowout preventer ( 3 ). The equipment ( 10 ) is withdrawn from the lower cavity ( 9 ) upon completion of deepening, the device ( 7 ) is closed during separation of the cavity ( 9 ) from the cavity ( 8 ) and cutting-off the hydraulic connection between the producing formation and the upper cavity. The technical solution increases the efficiency and quality of technical operations and prevents the undesired inflow of formation fluids.

1 . The method of completion of a well equipped with the producing string, downhole equipment (drill string), blowout preventer, comprising lowering the producing string into the producing formation top, installation of the downhole equipment (drill string), deepening of the well to the budgeted depth with circulation of the washer fluid, prevention of fluids inflow formation, lifting of downhole equipment (drill string) and fixation of producing formation bedding interval, differing in that the sealing device is lowered on the producing string, which divides the well into the upper and the lower cavities with the hydraulic connection between the well opening and the upper cavity and between the lower cavity and the producing formation, respectively, capable of rotation; the check valve and the downhole equipment (drill string) are installed step-by-step down to the sealing device, the washer fluid is replaced with the washer fluid creating the hydrostatic pressure less than the formation pressure, the downhole equipment (drill string) is passed through the sealing device which is capable of separating during the downhole equipment (drill string) installation and re-establishment of the hydraulic connection between the well opening, the upper cavity, the lower cavity and the producing formation along the annular channel, the well is deepened with the help of the downhole equipment (drill string) located in the lower cavity of the sealing device until the formation fluids inflow occurs, with adjustment of the differential pressure in the hydraulic system “well opening—producing formation” by means of the check valve and the blowout preventer, the downhole equipment (drill string) is removed upon completion of deepening from the lower cavity with closing of the sealing device and separation of the lower cavity from the upper cavity and cutting off the hydraulic connection between the producing formation and the upper cavity.