Author Archives: DrillingFormulas.Com

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Working in the oil field and loving to share knowledge.

What is Top Drive System?

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A top drive is a big motor system which is hoisted in a derrick or mast of a drilling rig. A top drive is a modern rotating system which has been popular for many drilling contractors and oil operators. Top drives can be used on all types of rigs, from truck-mounted rigs to offshore rigs.

top-drive-system

Rotation provided to a drill stem is accomplished by a top drive. Therefore, a Kelly and a Kelly bushing are not required for a top drive system. Moreover, a master bushing and a rotary table serves as support for slip and weight of a drill stem and as a conduit for a drill stem to be raised or lowed into a wellbore. Continue reading →

Gel Strength and Operational Impact

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The gel strength is the shear stress of drilling mud that is measured at a low shear rate after the drilling mud has been static for a certain period of time. The gel strength is one of the most important drilling fluid properties because it demonstrates the ability of the drilling mud to suspend drill solid and weighting material when circulation is ceased.

gel-strenght

How can gel strength is measured?

Gel strength measurement is made on viscometer using the 3-rpm reading, which will be recorded after stirring the drilling fluid at 600 rpm to break gel. The first reading is noted after the mud is in a static condition for 10 seconds. The second reading and the third reading will be 10 minutes and 30 minutes, respectively. Continue reading →

Have You Seen How A Jack Up Rig is Launch into the Sea?

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A jack up rig which is one of offshore mobile drilling units is widely used in shelf offshore drilling exploration and production. The unit consist of a buoyant hull fitted with jack up legs which can be raised up or down into the sea bed.

These videos are very fascinating to see because this is how shipyard launch brand new jack up drilling units into the sea. Some major components of a jack up rig such as hull, jack up legs, accommodation are fabricated when the unit is on land. One major component which is derrick will not be installed until a jack up is into the water.

launch-jack-up-rig Continue reading →

Yield Point (YP) of Drilling Fluids

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Yield Point (YP) is resistance of initial flow of fluid or the stress required in order to move the fluid. It can be simply stated that the Yield Point (YP) is the attractive force among colloidal particles in drilling fluid. As per Bingham plastic model, YP is the shear stress extrapolated to a shear rate of zero.

Figure 1 - YP is a shear stress at zero shear rate.

Figure 1 – YP is a shear stress at zero shear rate. Continue reading →

Viscosity of Drilling Mud

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Viscosity describes a substance’s resistance to flow. High-viscosity drilling mud is typically described as “thick,” while low-viscosity mud is characterized as “thin”. In the oilfield, the following terms are used to describe drilling fluid viscosity and rheological properties. Two viscosities that will be described in this section are Funnel Viscosity and Plastic Viscosity.

 Funnel Viscosity

The funnel viscosity is timed in seconds of drilling mud flowing through the Marsh Funnel Viscosity. The Marsh funnel is easy-to-use equipment that is used to quickly check viscosity of the mud. The Marsh funnel is dimensioned so that the outflow of time of one quart of freshwater (946 cc) at a temperature of 70 F ± 5 F (21 C ± 3 C) in 26 ± 0.5 seconds.

Figure 1 - Marsh Funnel

Figure 1 – Marsh Funnel Continue reading →