Method for drilling ultra-shallow layer thick oil horizontal well by using vertical well drilling machine drill

Abstract

The invention relates to a method by using a vertical shaft drilling machine to drill superficial thick oil horizontal well. The invention is characterized in that: during the process of wellbore control of the drilled well, kick-off orientation is to utilize a compass to determine wellbore azimuth; marks are made on a rotary disc and a drilling tool entering into the well; when the drilling tool enters into the well, angular difference is accurately measured; when the drilling tool is drilled to a kick-off point, angular difference between the high side of a screwdrill and the designed wellbore azimuth is computed according to angular difference records, and the high side of the screwdrill and the designed wellbore azimuth are made to be aligned by rotating the drilling tool by a certain angle, and then kick-off drilling is performed. When a sleeve is descended, a pressure device is arranged on a well head or a pressure boosting joint is arranged on an adequate position of a casting string, and then the casting string is made to smoothly descend to a designed position by means of arranging weighted drilling fluids inside a pipe. The method provided by the invention is mainly used for wellbore track control of the superficial thick oil horizontal well and descending operation of the casting string.

Description

technical field [0001] The invention relates to drilling operations in oil and gas fields, in particular to a method for drilling ultra-shallow heavy oil horizontal wells with a vertical well drilling rig. Background technique [0002] At present, for ultra-shallow heavy oil reservoirs, conventional vertical well steam injection huff and puff production methods are mostly used for production, which has problems such as poor production effect, rapid production decline, low or even no comprehensive economic benefit. The use of horizontal wells for production can more effectively increase the exposed area of ​​the oil layer, expand the range of steam thermal flooding, and increase the recovery rate. This has been confirmed in the inclined and straight horizontal wells completed by using inclined and straight well drilling rigs in the early stage. However, the practical application shows that the inclined vertical horizontal wells drilled by the inclined well drilling rig have o...

AI Technical Summary

Problems solved by technology

However, due to the shallow burial depth of ultra-shallow heavy oil reservoirs, there are a series of insurmountable technical problems in drilling horizontal wells with vertical drilling rigs

For example, the vertical well section is short, and there is little room for adjustment of the wellbore trajectory. However, if the current relatively economical measuring instruments want to be precisely oriented, they must avoid the magnetic interference of the upper casing. vertical well sections become more limited, increasing the difficulty of well trajectory control

In addition, in shallow heavy oil horizontal wells, the frictional resistance generated during the running of the casing string is relatively large, and the running force of the casing string during the general casing running process is provided by the weight of the casing string itself in the vertical well section and small well deviation. In ultra-shallow heavy oil horizontal wells, the weight of the pipe string that can provide downward force is relatively small, and conventional vertical drilling rigs do not have the ability to pressurize the drilling rig. Therefore, it is difficult to run casing strings in ultra-shallow heavy oil horizontal wells.