On May 5, ji10h well, the key exploration well of Tuha oilfield, applied the split sidewall repair device. The drilling depth was more than 5000 meters, and the whole process was safe and smooth, which proved the effectiveness of the split sidewall repair device in deep well drilling.
In recent years, the number of deep exploration wells and ultra deep horizontal wells drilled in Turpan Hami oilfield has been increasing. Salt gypsum layer, hard brittle mudstone, coal measure stratum and fracture zone stratum are developed from top to bottom. The complex situation of “shrinkage, resistance, collapse and jamming” is easy to occur in the drilling process. According to incomplete statistics, more than 90% of the resistance and clamping positions are located on the under sized or full eye stabilizer. Once the stabilizer is seriously worn and cannot be flexibly replaced, the drilling will be affected.
Tuha Oilfield Engineering Technology Research Institute has designed and developed a split wellbore repair device in order to open up the borehole “thrombus” and improve the safe drilling ability, innovatively put forward a new idea of active prevention and treatment of downhole complex accidents during drilling and completion.
The split shaft wall repair device takes the multi-functional cutting wing as the core component, the back of the uphill body and downhill body are equipped with sharp conical teeth, and the replaceable shell part is added; The functions of repair, cutting and rock breaking are integrated into the tool design to realize the transformation from the function of centralizer to the function of “preventing complexity + handling complexity + controlling well deviation”, which can repair the well wall efficiently while drilling and make the well hole more regular and smooth; The shell can be replaced, which meets the multi-functional deviation control requirements of the same screw drill, provides a new technical way to quickly solve the complex situation of the wellbore, and ensures the smooth wellbore and solid completion operation.
Through field scale application, the split sidewall repair device has greatly improved the safe drilling capacity and production efficiency. The average complex accident efficiency has been reduced to 1.74%, and the drilling cycle has been shortened by 23.5%. A new method of downhole complex while drilling prevention and treatment has been formed, which provides technical support for the low-cost and cost-effective development of deep and complex wells.
The split sidewall repair device has been popularized and applied in 111 horizontal wells and deep exploration wells in Santanghu, northern piedmont zone, slope area, Zhundong mining right transfer new area and other blocks of Tuha oilfield, and has obtained the national utility model patent, saving the cost of Tuha oilfield by 12.1906 million yuan and shortening the drilling cycle by 1533 days.