Exploratory drilling: features, equipment. Assistant driller for production and exploration drilling

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Exploration drilling is an activity aimed at finding raw materials in the bowels of the earth. At the beginning of the 19th century in France, they searched for water in this way. In the 50s of the same century, oil was searched for with the help of exploratory drilling.

The essence of the process

Today, exploration wells are drilled with powerful and sophisticated equipment.

A special chisel is used to destroy the rock. It is attached to the drill pipes. In the process of exploratory drilling, the bit wears out, respectively, it needs to be changed. To do this, the pipe string rises, the worn element is removed, and a new one is screwed on. After that, the entire column descends into the bowels of the earth again.

The chisel has a larger diameter than the pipes. After it passes through the rock layer, a gap remains between it and the pipe. With the help of powerful pumps, the drilling fluid is fed into the pipes. It descends first down, and then rises up the annulus. At the top, it is cleaned of rock and re-injected into the well. These worksare performed by qualified specialists - drillers of operational and exploratory drilling. Of course, a whole team works at one facility.

Improving technology

In 1922, the Soviet engineer Kapelyushnikov proposed a new method of exploratory drilling - turbine drilling. An engine was lowered to the bottom of the well, due to which the bit rotated. This innovation eliminated the need to drive the entire pipe string, saving significant energy.

Subsequently, the method of turbine exploratory drilling has been improved many times. Today, a turbodrill is the most complex unit, the length of which is about 10 m. Each stage of the machine is equipped with 2 disks with profiled blades. One of them is a stator. It is permanently fixed in the body of the unit. The second is a rotating rotor. The turbodrill is driven by drilling fluid injected into the well under pressure. It washes out the remaining rock and cleans the rotor blades.

A relatively small power is developed on each section of the unit. However, the combined force is enough to break even the hardest rocks.

Drilling fluid

His quality is given increased attention. The drilling fluid performs several functions. First of all, he raises fragments of destroyed rock to the surface. In addition, due to it, the turbodrill is set in rotation, the bit is cooled.

Water used to be the drilling fluid. It is currently not in use. Due toit's next. Water is really capable of carrying the destroyed rock to the surface. However, if the process is stopped, all debris will begin to settle down. After some time, they will fill the annular space. As a result, all equipment will remain under the rubble. Pulling the unit is almost impossible. All this will entail serious financial losses, since the cost of the machine and its elements is several million rubles.

To avoid such situations, a special clay mortar based on clay powder is used. It does not allow the rock to settle in case of suspension of drilling. After the resumption of the process, the sludge (destroyed rock) will go up again.

Difficulties

When drilling in the subsoil, there may be different layers (oil, water, gas). One of the key conditions of the process is to ensure their immunity.

Let's say a 4 km hole with a diameter of 30 cm is drilled. Conventional sealing from above will lead to very dangerous consequences. Mixtures from different layers will begin to fill the space. Then, from the reservoir, in which the highest pressure, substances will penetrate into other levels. They, in turn, may contain water layers close to the surface. As a result, oil or gas will seep into lakes and rivers, urban reservoirs.

Problem Solving

To prevent such consequences, the wellbore is filled with drilling fluid during the drilling process. It prevents the penetration of fractions from occurring layers intoeducated space. But in order to achieve this, a solution of a certain density is needed, and it should not penetrate into the formations.

Assistant driller of production and exploration drilling

As mentioned above, several workers are involved in drilling. The crew includes not only highly qualified drillers, but also support staff.

Drill Assistant:

• takes part in the process;
• starts rig under driller control;
• performs riding work during round trips;
• participates in the laying of casing and drill pipes;
• prepares and processes the solution;
• starts, stops the pumps, controls their operation, flushing fluid level;
• identifies and repairs faults, replaces worn pump elements.

The duties of the employee also include participation in the elimination of accidents and complications.

Qualification requirements

The assistant driller should know:

• technical regulations for drilling technology, organization of work;
• main geological characteristics of deposits;
• features of the technological process of oil, gas production, extraction of other minerals;
• technical characteristics and arrangement of tools, equipment, mechanisms, rules for their use.

Because the worker's tasksservice of the units is also included, then he must know the rules for preparing, cleaning, processing solutions, their main physical and chemical parameters, the rules for preparing pipes for running, drilling rig schemes, operating instructions for blowout prevention equipment.