Most critical steps of geothermal well construction
1: the selection of rig equipment is deeper than predicted. If you ca n’t select the deeper, you can press the deeper to avoid the emergence of unexpected situations.
2: to maintain the vertical maximization of the drilling, it is best not to bend too much, so as to avoid accidents in the well, and can effectively reduce the wear on the wall of the well and extend the service life.
3: Strictly use flushing fluid for drilling. It is strictly forbidden to use thick mud for drilling in hot reservoir. Accurate drilling geological cataloging and strict and correct geological stratification must be sloppy, because the staff must make judgments based on the geological changes in drilling and find out countermeasures, modify and improve in time Geological design plan.
4: maintain a reasonable wellbore structure and strict cementing, specifically the surface pass diameter and run-in depth should fully consider the needs of the water intake equipment caliber and run-in depth; the well wall pipe should run into a certain depth of the thermal storage and be strict Seal the upper layers of the top plate of the thermal storage as far as possible to achieve 3 or 4 diameters to the bottom of the hole.
5: accurate drilling geological cataloging, strict and correct geological stratification, because the staff should make judgments on possible problems based on the geological changes in drilling, find out countermeasures, modify and improve the geology in time Designed plan.
6: Logging should be carried out before entering the surface pipe, well wall pipe, and when reaching the design depth, to carry out geological stratification in conjunction with the geological catalog, to understand formation temperature changes and permeability and water cut characteristics of thermal storage, to guide Drilling construction.
7: Well drilling and productivity testing should be carried out in time when drilling is completed, and the stagnation time is strictly prohibited. Well washing should adopt different methods for thermal reservoir formation characteristics, drilling depth, mud properties and consistency used. The final productivity test should meet the specifications Claim.