What is the longest, deepest and largest hole ever drilled on earth?

by DrillingFormulas.Com on December 21, 2014

This is very interesting information about the longest, deepest and largest hole ever drilled on earth. You will be amazed how people can overcome the limit of nature.


Longest Hole

In May 2008, GSF Rig 127 operated by Transocean drilled (BD-04A) in the Al Shaheen Oil Field for Maersk. It has a measured length of 40,320 feet (12.3 km) with a horizontal section of 35,770 feet (10.9 km). Maersk Oil’s well also extended the company’s previously held world record for the longest horizontal well by 9,000 feet (2.7 km). The entire horizontal section of the well is placed within a reservoir target which is only 20 feet (6 m) thick. And it was completed in 36 days. Incident free. [click to continue…]


Beautiful Oilfield Calendar 2015 Free Download

by DrillingFormulas.Com on December 20, 2014

In next few days, we will pass 2014 and start a new journey in 2015. For this year, we would like to make a special oilfield calendar 2015 for everybody. There are a total of 12 months with different themes and you click on each image to download the big files. You can set each photo on your computer screen.


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Choke Line Friction – How Does It Affect Deepwater Well Control?

by DrillingFormulas.Com on December 16, 2014

Choke line friction (CLF) is the frictional pressure which is generated while circulating mud through choke or kill line. For surface stack, the choke line friction is negligible because the choke line is short therefore the friction pressure is so small. However, the choke line friction in deepwater operation has a big effect bottom hole pressure. Killing the well without considering the CLF will add excessive pressure and it increases the chance of fracturing formation at casing shoe or anywhere in the well.

choke-Line-Friction [click to continue…]


Oilfield Casing Data Sheet Free Download

by DrillingFormulas.Com on December 12, 2014

Casing information is very important part of working in the oilfield. This information is used in several calculations as expected displacement volume, cement calculation, stuck pipe calculation, burst/collapse, casing design, etc. Therefore our team collects casing data into one spreadsheet and pdf file for you to download.


What is Information inside the Casing Data Spreadsheet?

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Lost Circulation and Well Control

by DrillingFormulas.Com on December 8, 2014

Lost circulation is a situation when drilling fluid losses downhole because formation(s) is fractured. There are three levels of lost circulation which are seepage loss, partial loss and total loss.


Seepage loss is a situation when the mud volume loses into formation at very minimal and this will have no or little effect for a drilling operation.

Partial loss is a situation when some volume of drilling fluid loses into the well and you get some drilling mud volume back on surface. Not only do you lose the fluid volume, but you may have ballooning issue to deal. However, this type of fluid loss will not lead to well control situation because the total hydrostatic pressure does not decrease.

Total loss is the worst situation because there is no mud returning back to surface and the mud level will drop to any level down hole. Losing a lot of fluid into the well will directly affect hydrostatic pressure at the bottom. If you cannot keep the hole full, it might be a time when the hydrostatic pressure is less than the reservoir pressure. Eventually, a well control situation will be happened. [click to continue…]


Something wrong while pulling out

by DrillingFormulas.Com on December 7, 2014

This is a few second vdo showing how fast the unexpected can be happened on the rig floor while tripping.

What was happened?

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Oilfield Salary Survey and Comparison Study Based on Q3 2014

by DrillingFormulas.Com on December 4, 2014

We’ve collected salary information from the most trusted oilfield website, rigzone.com, about salary and compensation for Q3 2014. At this time, we have the comparison between Q1 salary and Q3 salary.


Oilfield Salary Based On Geographical Locations Based on Q3 2014 Data

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Gas behaves differently from fluid therefore you cannot use a simple hydrostatic formula to determine reservoir pressure. Gas is compressible but fluid is incompressible.


The formula to determine the bottom hole pressure of dry gas well is shown below;

equation 1


Where; Pbh = bottom hole pressure in psia (absolute pressure)

Pwh = wellhead pressure in psia (absolute pressure)

H = true vertical depth of the well

Sg = specific gravity of gas

R = 53.36 ft-lb/lb-R (gas constant for API standard condition air)

Tav = average temperature in Rankin (Rankin = Fahrenheit + 460) [click to continue…]


You Need To Watch This – Dropped Casing Incident

by DrillingFormulas.Com on November 23, 2014

Dropped object is one of the most dangerous accidents on the rig therefore we would like to share this footage so you need to watch this. This short VDO can change your life.


You really need to watch this.

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Magnetic and gravity tooสface are terms in directional drilling world to describe the direction of the well. They are different in meaning and application therefore this article will teach you about these terminologies and how to read it.


Magnetic Toolface
The magnetic toolface is an angle projection onto the horizontal plane between the tool face and magnetic north. Typically, directional tools use the magnetic tool face when the inclination is less than 5 degree. The Figure 1 demonstrates that the mud motor is lined up to kick off at 30 degree azimuth magnetic.

Figure 1 - Magnetic Toolface
Figure 1 – Magnetic Toolface [click to continue…]