![]() ![]() Therefore, if the annular ascending velocity of the drilling fluid is faster than the settling rate of the drill cuttings, the drill cuttings are carried out of the hole. In vertical rotary mud drilling, gravity is pulling the solids downward while the flow of drilling fluid is in the opposite direction. > There’s no need to reduce water level under conditions of high ground water.The biggest difference between drilling fluids for vertical rotary mud drilling and horizontal directional drilling (HDD) applications is in the requirements for gel strength. > There’s no need to have external power supply during the drilling due to complete machine autonomy > Shortening of accident risks, and as a result they guaranty to keep a pipeline in operating state for long > Significant shortening of heavy machinery and workers number using for laying pipelines > Significant shortening of the time for work performance due to using high technological drilling complexes ![]() > Shortening of terms and volumes of organizational and technical agreements before start to work it’s possible as there’s no need to stop all kinds of transport and/or block motorways and railways under conditions of urban housing system if a line is planned to build under motorways, street railways, roads, public gardens and parks in guarded areas of high voltage overhead lines, main gas, oil pipelines under rivers, gullies, forest areas in specific soils (rock, quicksand) > Capability of trenchless construction, repairing and cleaning underground pipelines: Production and technical aspectDigiTrak Mark III Water or bentonite is pumped under regulated pressure through the drilling head is at the final point a drilling machine spindle, then through the drill rod reaching the drilling head. In this way the drilling is carried out on the given path. After that the drilling head moves forward on X per cent conforming to an operator’s command, then the drilling machine operator starts to pump water or bentonite with the tool rotation. Connected in such a way drill rods look like a flexible rope that is used for cleaning sewerage pipes.Īn operator can see a turning angle of the drilling head and its direction on the hand locator display, and if it’s necessary to change the drilling direction he gives a drilling machine operator the order: ‘Stop’, and then ‘Rotate by X degrees’ (but it can be done only in one direction conforming to involvement direction of a drill rod threads) in order to place the drilling head in the right direction and commands: ‘Move the tool on X per cent forward’. The drill rods are connected to each other one by one as the drilling head moves. At the ends of the drill rod are conic outside and inside threaded couplings at different ends of the rod. The drill rod is a pipe sized of about 60-80mm in diameter and 1-3m long. The drilling of the pilot hole is completed when the drilling head is at a given exit point according to the project. Then the drill rods are pushed without rotation in order to correct the drilling path. In case of the deviation of the drilling head from the project path a machine operator stops drill rod rotation and corrects the direction of the drilling head. The data is extremely important for controlling the path of laying pipeline with the project documentation and minimising the risk of bending the operating rod. The information is also shown on the machine operator’s remote display. Visual information about position, angle and azimuth of the drilling head is showed on the locator display. The control over the location of the drilling head is exercised by the means of a special receiving gear – locator that receives and handles signals from a transmitter built in the drilling head case. Drilling fluid reduces friction of the drilling head and a drill rod, stabilises the bore hole, cools the rock-cutting tool, washes away the rock and removes the cuttings. The drilling head has two water ports to feed special drilling fluid that is pumped in a bore hole making suspension with crushed rock. The drilling head is fastened to the flexible drive bar by means of a hollow pipe it allows control in the process of drilling the pilot hole and get round detected underground obstacles in any directions within a usual bend in the extended operating rod. It is done with the help of a rock-cutting tool – a front- beveled drilling head with an installed transmitter. Drilling a pilot hole is one of the important stages of the work, influencing considerably on the result.
0 Comments
Leave a Reply. |