Guide to dealing with common drilling problems: How to deal with stuck pipe, slurry leakage and other problems

Guide to dealing with common drilling problems: How to deal with stuck pipe, slurry leakage and other problems

During the drilling process, problems such as stuck pipe and mud leakage are not uncommon. Staying calm when encountering and following scientific handling ideas and steps is the key to solving problems. Here are practical guidelines for dealing with two of the most common dilemmas.

1. Drill stuck: The drilling tool is "bitten" in the well

Identification: The drilling tool cannot rotate or lift normally, or the range of movement is extremely small, accompanied by abnormal load.

The principle of handling: move first, then clear the jam, and avoid being reckless. The processing flow should follow the principle from easy to difficult, from simple to complex.

Coping steps and methods:

Try active drilling tools now:

Within the capabilities of the machine, try to alternate forward and reverse rotations, and at the same time cooperate with different strengths of lifting and lowering. The movement should be gentle, and use vibration and torque to try to loosen the stuck part.

Absolutely prohibited: Using the maximum pulling force to forcibly lift the drill pipe without identifying the cause can easily cause the drill pipe to break and complicate the accident.

Determine the type and cause of stuck drill:

Mud-skin adhesion stuck: It is easy to occur in soft and water-absorbing swollen strata (such as clay layers). You can try pumping in clean water or a special jam-removing agent with a large displacement to soak and lubricate the well wall.

Falling objects or well wall collapse: Drill stuck: caused by falling rocks or unstable well wall. If the activity is ineffective, more specialized tools may be needed.

Use a jar or professional tool:

If conventional activities are ineffective, a jar can be inserted into the drill pipe and a strong upward or downward impact can be used to release the jam.

If the problem still cannot be solved, professionals need to use a reverse thread drill pipe (reverse buckle drill pipe) to unwrap and remove the drilling tool above the stuck point, and then process the remaining parts in the well. This operation is highly technical, so do not attempt it on your own.

Preventive measures: Keep the mud performance in good condition, quickly pass through the easily collapsed formations, trip out the drilling smoothly, and check the drilling tools regularly.

2. Mud leakage: Drilling fluid goes out but never returns.

Identification: The mud or water pumped into the well cannot return to the surface, or the amount returned is much less than the amount pumped in, and the liquid level in the well drops.

Treatment principle: first determine the severity, and then block it accordingly.

Coping steps and methods:

Determine the type and severity of leakage:

Permeability loss: The leakage rate is slow, and a small amount of mud returns. Usually caused by pores in the rock.

Crack or cave leakage: The leakage rate is fast and the mud does not return at all. Underground cracks or small caves are often encountered.

Targeted measures:

For minor leaks:

Add leak-stopping materials to the mud, such as fine mica flakes, sawdust, special leak-stopping agent, etc.

Increase mud viscosity and shear force to form a dense mud cake in the leakage layer.

For severe leaks:

Use the bridging leakage plugging method: put inert materials of different particle sizes (such as walnut shells, gravel, fibers) to build bridges and block the entrance to the leakage layer.

Use quick-setting cement or special chemical sealing slurry for sealing. This method has high technical requirements.

If the leakage layer is shallow and cannot be plugged, consider running casing to isolate it and then continue drilling.

Adjust operation strategy:

When leakage occurs, the pump displacement and drilling pressure should be reduced to reduce the impact on the formation.

Try to quickly pass through the leakage layer and enter the lower stable formation.

Preventive measures: Understand regional geological data in advance, use anti-leak mud in advance in strata that may be lost, and control drilling parameters.

Common Security and Collaboration Principles

Maintain communication: When encountering problems, operators should maintain close communication with the on-site person in charge and experienced masters to analyze and make decisions together.

Record details: record the well depth, formation, phenomenon and treatment process when drill stick or mud leakage occurs, to provide valuable experience for subsequent operations.

Clear boundaries: For complex or vicious drill stuck or leakage, if the on-site conditions and technical capabilities are limited, support from an external professional team should be sought in a timely manner to avoid the expansion of accidents and sharp increases in costs due to forced handling.

Summary: In the face of stuck drill and slurry leakage, the core is to accurately determine the cause, take targeted measures, and always put safety and prevention first. A set of robust processing procedures and rich experience are the greatest guarantees for overcoming these drilling problems.