The highest stage of drilling technology development is automatic drilling. The so-called automated drilling is: the whole drilling process relies on sensors to measure various parameters, and uses computers to collect, comprehensively interpret and process, and then issue instructions, and finally the relevant equipment automatically executes, making the entire drilling process an unmanned operation. Automatically control the process. In the process of automatic control of drilling mud pumps, downhole measurement while drilling and downhole automatic control are the key links and key technologies. The combination of the two is actually the technology of automatic control of wellbore trajectory—steering drilling technology.
Steerable drilling technology is a high-tech in the field of drilling engineering, representing the most advanced development direction of drilling in the world. At present, horizontal wells, extended-reach wells, lateral wells and other difficult and complex wells are flourishing and widely used in the world. Traditional drilling technology cannot meet the operational needs of these difficult wells and must rely on advanced drilling mud. The guiding technology of pump accessories can ensure the accuracy of wellbore trajectory.
1. Geometry orientation
The drilling mud pump is measured by the downhole measurement while drilling tool to measure geometric parameters, and the values of well deviation, azimuth and tool face are transmitted to the control system, and the control system corrects and controls the wellbore trajectory in time.
Geosteering is to control the wellbore trajectory in real time according to the geological parameters (formation lithology, formation level, oil layer characteristics, etc.) obtained from logging while drilling while having geometrical steering capabilities, so that the drill bit can be positioned along the optimal position of the formation. drilled into. This allows optimal control without prior knowledge of formation properties. Geosteering can use the geological formation parameters collected in real time near the drill bit to predict and identify oil and gas layers in advance, and adjust the well trajectory as needed to guide the drill bit to accurately drill oil and gas enriched areas. The key technology of geosteering is the real-time measurement of formation parameters near the drill bit, wellbore trajectory parameters and drill bit working parameters.
1. Sliding guide tool
The characteristic of the sliding steering tool is that the drill string does not rotate during the steering operation, and the drilling mud pump drill string advances with the drill bit and slides along the well wall. Sliding steering has many disadvantages: the torque and friction of the drill string are large; the wellbore cleaning is not thorough; the drilling speed is slow, etc., but it is still dominant at present. Downhole power drilling tools are mostly used in directional drilling, and the main sliding steering tools include: motor curved housing, adjustable curved joint, variable diameter stabilizer, etc.
2. Rotary guide system
The rotary steering tool directly guides the drill bit to drill along the desired trajectory, so as to avoid the drill string sliding on the well wall, so that the wellbore can be cleaned well, and at the same time, it allows the selection of a suitable drill bit according to the formation. This can significantly reduce or eliminate the deficiencies of sliding guide means. At present, rotary steerable tools mainly include: automatic vertical well drilling mud pump system, automatic vertical well drilling system, automatic directional drilling system, rotary steerable drilling system, rotary closed-loop drilling system, etc.
1. It has the ability to guide when the drill string of the drilling mud pump rotates.
2. It can be used together with the downhole motor.
3. Equipped with a full range of standard detection instruments for formation parameters and drilling mud pump parameters.
4. Equipped with a surface downhole two-way communication system, it can send commands from the ground to change the wellbore trajectory according to the data transmitted from the downhole without drilling.
5. Modularization and integration of tool design and manufacture.
6. It can be used in high temperature wells above 150°C.
7. No special drilling parameters are required, the drilling mud pump can ensure the optimal drilling process.
8. Steering is automatically controlled to ensure accurate and smooth wellbore trajectory.