HORIZONTAL WELL DRILLING METHOD Russian patent published in 2023 - IPC E21B7/04 E21B44/02 

FIELD: well drilling.

SUBSTANCE: invention relates to the drilling of a horizontal well and, in particular, to the optimal control of this drilling with the condition of ensuring that the horizontal wellbore is located between its roof and base. The essence of the invention: the method determines the type of rocks in real time while drilling a well at the location of the rock-cutting tool. This is carried out using a set of geological and technical data to set drilling modes - its speed, axial load on the rock-cutting tool, the latter’s torque and revolutions. To do this, in given drilling intervals of the horizontal part of the wellbore, lithological groups of rocks are identified - reference points that characterize the reservoir, non-reservoir and dense layers of the reservoir, influencing the above-mentioned drilling modes. A number of reference wells are selected with bottom hole coordinates close to the current coordinates of the well being drilled and rock groups similar to the rock group of the well being drilled. Additionally, historical data on previously drilled wells in the area of the well being drilled is used, characterizing the mentioned drilling modes. During the drilling process, the rock types of the well being drilled are analysed, compared with the rock types of the reference wells, and the functional dependence of the reference points - a group of rocks - on the drilling modes is established. Based on the lower correlation coefficient of the compared data, the corresponding reference well is selected in real time as a reference well to ensure drilling of a well between the roof and the bottom of the reservoir. At the same time, they prevent the opening of the roof and/or sole. During the drilling process, the zenith angle of the well and the permissible distances to the roof and/or bottom of the reservoir relative to the position of the rock-cutting tool are continuously monitored. If necessary, adjust the well drilling trajectory. Control over the position of the rock-cutting tool is carried out automatically with individualization of the drilling site along the internal and external characteristic boundaries of the reservoir layer and the use of continuous geophysical research, including in front of the bottom of the drilled well.

EFFECT: increasing the efficiency of drilling management by preventing unnecessary operations to adjust drilling and speeding up decision-making on changing the drilling trajectory in real time.

6 cl