A hole opener is used when the successive hole sections could have been drilled using regular drilling bits but where, for one reason or another reason, a reduced diameter hole section known as a pilot hole was required at a particular depth. It is designed to fit onto the drill string and is commonly used …
Jars are approximately thirty feet long. Heavy-duty lift subs for tapered shoulder elevators are typically used for handling. Jar Safety Clamp When handling the Drilling Jar above the rotary table, the safety clamp must be on the Jar. This keeps the Jar in a safe, extended position while being handled. The safety clamp is removed …
Stick-slip torsional drill string vibrations manifest in low-frequency torque fluctuations of significant amplitude during drilling or coring operations. It is often seen as a groaning noise emanating from the top drive or rotary table. The period of oscillation is typical of the order of 2-10 seconds. This period corresponds to the first eigenfrequency of the …
Subs are short pieces of tubular material used to increase the versatility of the main component of the drilling string. The simplest is a crossover sub, which connects two items with different threads. Others used in the drill string are: Crossover Drilling Sub These are short sections of drill collar material 0.6 m (2 ft) …
In general, the neutral point can be defined as the point in the drill string where there is a change from tension to compression in the axial stress or the point that is zero tension and zero compression. The location of this neutral point depends on WOB and the Bf buoyancy factor (that depends on …
When manufactured, the new drill pipe will be subjected by the manufacturer to a series of mechanical, tensile, and hydrostatic pressure tests & inspections by API Specifications 5A and 5AX. This will ensure that the pipe can withstand specified loads. A joint of drill pipe will however be used in several wells. When it has …
Mechanical drilling jars are different from Hydraulic Drilling Jars Operation & Mechanism as it has a preset load setting that must be applied before the jar will fire. They are sensitive to load only and not time. To increase or decrease the jarring tension, the jars must be tripped to the surface, in other words, …
A hydraulic Jar is one of the drilling jar types used in drilling operations to free stuck pipe problems. This article will introduce the hydraulic drilling jar operation and mechanism. We also recommend visiting Drilling Jar Placement, Types, and Calculations. Operation & working principle article Hydraulic Drilling Jar Mechanism The tripping (check also: Tripping pipe …
In General, the Bending Strength ratio BSR is the ratio of the relative stiffness of the box to the pin for a given connection. The predominant consideration, especially in selecting larger Bottom Hole Assembly BHA connections, is (BSR). In Drill String Design, If we select a connection with either a pin or box that is out of …
In general, we can define the burst pressure in drill pipe as the differential pressure acting across the drill pipe wall due to an internal pressure greater than the external pressure. In this article we shall discuss the drill pipe burst pressure formula & calculations which is used in drill string design. How To Consider …
