Analysis of the causes and treatment measures of common drilling tools stuck in bridge drilling 5

Drilling accident treatment --- hydraulic pipe cutter.

One: Specifications. It is suitable for handling the inner and outer pipes of PQ, HQ, NQ, BQ series drilling tools.

The weight of the BQ model only.

Cutter elongation 10 mm --15mm.

The shear pin shear force is 10kn--15kn.

Two: working principle.

When the pipe cutter is connected with the drill pipe to reach the predetermined position, the large pump is opened to press the water, so that the piston moves downward, and the lower tapered rod of the piston pushes down the three groups of cutters to open outward at the same time, contacts the inner diameter of the accident drill pipe, and turns around, that is, begins to cut the accident drill pipe (casing).

There is a set of springs inside the tapered rod, and as soon as the pump is stopped, the extended cutter head is immediately in place when there is no water pressure.

Three: use. It is mainly used to connect the drill pipe of a small level when the drill pipe in the hole cannot be raised after burning and card drilling, and enter the inner hole of the accident drill pipe, and cut it off with water pressure to push out the cutter head.

It can also be used for sectional lifting of the sleeve after the final hole.

Four: superiority.

1: Simplify the handling of accidents in the hole.

2: Save the cost of dealing with accidents.

3: Reduce scrap footage.

4: Reduction in mechanical accidents.

5: Improve the efficiency of Taiwan month.

Five: application industry.

Rope core drilling.

Possible causes: the appearance of probe stones or expansive soil strata, treatment measures to explore the lifting method, low-speed light lifting.

Reasons for stuck drilling: In addition to the complex formations that can make the drilling rig stuck in normal drilling, there are also the following reasons. In the area of mud and stones, the dust is not easy to discharge; chisel head broken wing; Negligence in manipulation, when the drilling was stopped for a long time, the rock powder was not blown clean, and the drilling tool was not lifted, so that the impactor was buried by the rock powder;

When drilling rock, stones fall from the hole wall or orifice or encounter large cracks and karst caves; Machine displacement or deflection of drilling tools in the hole during rock drilling; The new drill bit is larger than the original diameter; Mechanical experts explain in detail the reasons and treatment methods for drilling rig stuck drilling: drilling on the strength of the current drill bit, broken wings have been basically eliminated, once in case of special circumstances, a seamless pipe with a diameter of not much difference from the hole diameter, the pipe is filled with butter, asphalt and other substances, connected with the drill pipe into the bottom of the hole, the broken wing at the bottom of the hole is taken out, and the rock powder at the bottom of the hole is blown clean before salvage. In the more severe situation, the drilling tool can not be lifted, can not be put down, the impactor does not sound, at this time only the external torque or auxiliary tools to help the promotion, so that the drilling tool rotates, and then to give gas, while promoting the drilling tool, until the fault is removed.

When re-drilling, the pressure is slightly increased, and the propulsion force is gradually increased by drilling until the normal working pressure. You may be interested in the article: How small wind drilling equipment works and how it is introduced.

After the stuck drilling accident occurs, first of all, according to the lifting, lowering, rotation, opening pump circulation, as well as the wellbore situation and various phenomena before the stuck drilling, accurately judge the cause of the stuck drilling, and then take corresponding measures, but no matter what kind of stuck drilling, we must pay attention to adjusting the performance of the drilling fluid, remove the cuttings in time, clean the wellbore, and generally use the following methods to unstuck.

Lifting, (decentralizing) and turning the drilling tool to unclamp; bath well unchecker; Hit up, (click down) to solve the card; undercut sleeve milling card; **Undercut, sleeve milling; **, sidetrack new borehole.

Viscous suction card drill, collapse card drill, sand bridge card drill, diameter reduction card drill, keyway card drill, mud bag card drill, dry drill card drill can be used by the above methods from top to bottom, only the accident is lifted.

There are indeed seven ways to deal with stuck drills. So it's complicated, and it is recommended to go to the browser to query.

1.Shock, twist and unblock. Repeated attempts are made by lifting up, smashing down, turntable or top drive torque. If there is a vibrator while drilling in the drilling tool combination, the vibration will be activated repeatedly. It is also possible to install a ground vibrator on the ground to increase the intensity of the shock.

2.Bubble card decompression. The configuration of dejamming agent is generally based on oil to increase lubricity and soak and declamp.

3.Bubble acid hydrolysis card. After the anti-blocking agent is ineffective, acid can be soaked. Carbonate strata are generally soaked in hydrochloric acid, and other formations can also be soaked in soil acid. Let the acid react with the formation, expand or corrode the diameter of the well at the stuck drill, and the sticky card is dissolved.

4.Nest milling. Soaking and solving the card is invalid, there is only an undercut, or a loose buckle, take out part of the drilling tool, go down to the milling barrel, mill through the stuck drill, and then go into the fishing tool to salvage the fish.

5.If the milling is also difficult and ineffective, there is only one last resort: hit the cement, seal the stuck drill, and drill a directional well in the upper side.

There are many kinds, and there are 12 in the waning moon navigation

1. Geological reasons For geological conditions such as pebble strata, silt layer, and sand layer, it is easy to collapse holes;

Second, the selection of process methods.

1.The first is the selection of machinery, for pebble formations, percussion drilling rigs can be selected, for silty strata, sand strata use positive and negative circulation drilling rigs, sandy soils, all kinds of soft soils and weathered rocks can be selected rotary drilling rigs. At the same time, it should be noted that the drilling speed should not be too fast;

2.Secondly, in the mud solid wall, the specific gravity of the mud is selected and maintained, and the slurry surface height of the corresponding consistency and the mud inside the hole is prepared according to the porosity and water pressure of the sand layer, so as to resist the water pressure and prevent the collapse of the borehole;

3.Drilling sequence, drilling at intervals in one sequence and two sequences;

4.Orifice protection measures are in place, generally similar to the bottom layer, the orifice lock is required, and the orifice is minimized to disturbance;

5.In the hole cleaning stage, it is not messy whether it is one or two clear, pay attention to the consistency of the mud, as well as the cleaning speed;

6.Be careful not to hit the wall during the process of going under the steel cage.

Third, the quality control measures in the construction are not in place.

The retaining wall and hole wall are not firm and collapse the hole, resulting in pile breakage.

In the process of drilling, due to the special formation, improper selection of the type and performance of the drilling fluid, and poor quality of the well casing, the normal drilling cannot be maintained due to the obstruction, jamming, leakage, overflow and other conditions in the downhole; Accidents such as stuck drilling, drilling tool falling off and blowouts caused by poor inspection, illegal operation, and improper measures to deal with complex downhole situations are all complex drilling situations. Complex downhole accidents include well leakage, sticky suction drilling, borehole collapse drilling, sand bridge drilling, diameter reduction drilling, mud bag drilling, falling object drilling, dry drilling, cement drilling, etc.

Complex downhole accidents bring great difficulties to drilling engineering, which reduces drilling efficiency, increases drilling costs, and even leads to the scrapping of wells. Therefore, first of all, according to the specific conditions of the drilled well, effective measures should be taken to avoid accidents as much as possible. Secondly, after the occurrence of complex underground conditions or drilling accidents, it is necessary to carefully analyze and judge the causes and natures of them, formulate corresponding treatment measures, and deal with them scientifically to prevent them from expanding and deteriorating (Wang Jianxue et al., 2006).

a) Well leakage. Well leakage refers to a complex downhole situation in which working fluids (drilling fluid, workover fluid, cementing slurry, etc.) leak into the formation during drilling or workover operations. The visual manifestation of well leakage is the decline of the surface drilling fluid level, or no drilling fluid return from the wellhead, or the return of drilling fluid from the wellhead is less than the discharge of the anvil fluid.

After the occurrence of well leakage, the first step is to determine the location of the leakage, the second step is to determine the leakage pressure, the third is to determine the nature of the leakage channel, and finally the specific method and construction plan for dealing with the well leakage are determined in combination with the actual situation of the site.

The treatment of well leakage is indispensable for plugging materials, there are many varieties of plugging materials at home and abroad, which can be divided into several categories according to the mechanism of action, such as inorganic cementitious plugging materials, bridging plugging materials, high water loss plugging materials, temporary plugging materials and chemical plugging materials.

2) Sticky card drill.

The phenomenon that the drilling tool cannot move freely due to the adhesion and adsorption of the filter cake on the well wall is called sticky stuck drilling, and sticky stuck drilling is the most common stuck drilling accident in the drilling process.

After the occurrence of sticky card drilling, it can be treated by strong activities, shock and soaking declamping agent.

3) Hole wall collapse card drilling.

Due to the instability of the borehole, the rock fragments of the borehole wall fall into the well and jam the drilling tool. Collapse stuck drill is the worst type of stuck drill accident.

After the collapse of the stuck drill, it can be dealt with by means of mud pump circulation, strong activity, shock, injection and clamping.

4) Sand bridge card drill.

The cuttings in the well sink to the bottom of the well or stay somewhere in the well section, block the annular space, and bury the drill bit and part of the drilling tool to form a stuck drill called sand bridge card drilling, also known as grit card drilling, its properties are similar to that of collapsed card drilling, and its harm is worse than that of sticky card drilling.

The properties and treatment methods of sand bridge clamping are similar to those of collapse clamping, but the difference in treatment method is that if the cost of undercutting is too high or cannot be undercuted, side-drilling can be carried out.