Floating Egg

I did a simple science project with my 8-year-old daughter to show the action of buoyancy.

Step 1: Put a raw egg in a glass full of water. The egg sinks to the bottom.

Step 2: Keep adding salt and stir the water.  You will feel guilty of wasting too much salt, but eventually, the egg arises.

Before / After Adding Salt

My daughter and I were both amazed by this simple demonstration of buoyancy of salt water. Recall that Archimedes’ principle states that the upward force on a submerged object (egg) is equal to the weight of the water that it displaces. Salt water weights more than fresh water, this difference of upward force (buoyancy) makes the egg arise.

In drilling mud situations, saltwater drilling fluids can be formulated with high-density brines, such as calcium chloride, calcium bromide, etc. The mud weight is dependent upon the specific gravity (SG) of salts added and concentration of these salts. The heavier the mud, the higher the bottom hole pressure is. Note that one of the main functions of drilling fluids is to provide hydrostatic pressure to prevent formation fluids from entering into the well. Heavy mud brings some advantages and some disadvantages to other aspects of drilling operations because of the buoyancy it creates.

Buoyancy makes drill string appear light. This reduces the side force, which pushes drill string against wellbore. Therefore, there is less torque and drag for a heavier drilling fluid system, but what helps also causes problems in this case: too much buoyancy revokes the effectiveness of transferring the pipe weight to the bit.

When cementing a casing, due to the large size of the casing and the big difference of fluid densities in the annulus and inside the pipe, the buoyancy could be so great that the casing could be pushed out of the hole if it is not chained down.

Let’s use Dr.DE (drilling engineering tool box software) to show a couple of examples.

Consider an 11.75” OD casing with weight of 47lb/ft. The casing shoe is at 12,345 ft in a vertical well. The annulus is full of cement slurry of 16ppg. We assume mud weight of 8.33 ppg. With the help of Dr.DE the calculation shows that the casing will be lifted up.

Casing will be lifited up | Dr.DE - drilling toolbox

Casing Will Be Lifited Up

Now, change the mud weight to 9 ppg, due to this change, the hydraulic pressure inside the casing increases and the casing will not be lifted up by the buoyancy.

Casing will NOT be lifited up | Dr. DE Drilling Toolbox

Casing will NOT be lifited up

The Most Ancient Computer and the Latest Drilling Software

On December 5, 2013, the Chinese traditional method of calculations using the Abacus was listed as a UNESCO World Intangible Cultural Heritage. The Abacus, called Suanpan in Chinese, is considered as the world’s most ancient computer. It has more than 1,800 years of history. It is worth mentioning that others, such as Japanese cuisine, including sushi and the traditional food preparation methods and their culture have also been listed in the Intangible Cultural Heritage.

The following picture shows the Suanpan I bought a while ago at China town in Houston. It is so cool to have the ancestor of the modern computer in our office, especially since we are an engineering software company.

Abacus and Drilling Software

A typical Suanpan is about 20 cm (8 in) tall and it comes in various widths. It usually has more than seven rods. There are two beads on each rod in the upper deck and five beads on each rod in the bottom deck. This configuration is used for both decimal and hexadecimal computation. The beads are usually rounded and made of a hardwood. The beads are counted by moving them up or down towards the beam. The Suanpan can be reset to the starting position instantly by a quick jerk around the horizontal axis to spin all the beads away from the horizontal beam at the center.

Suanpans can be used for functions other than counting, for instance, very efficient Suanpan techniques have been developed to do multiplication, division, addition, subtraction, square root and cube root operations at high speed. Operating a Suanpan does not require electricity or batteries; only fingers are needed.

In the semiconductor industry there is Moore’s Law, which is an observation made in 1965 by Gordon Moore, co-founder of Intel. Moore’s law has proven that the number of transistors on integrated circuits doubles approximately every two years. Most experts, including Moore himself, expect Moore’s law to hold for at least another two decades.

No matter how fast technology evolves, some devices such as the Suanpan, still have the same design as when they were first invented. I don’t know if that’s good news for Suanpan manufacturers. As a software vendor, we have to continuously upgrade our drilling software, not for the sake of upgrading, but to include any new operation methods or new drilling tools that are being used in the field. Our latest Dr.DE (drilling engineering toolbox software) has migrated to the internet and has become a web-based application.

Web-Based drilling software - Dr.DE | Pegasus Vertex, Inc.

I really do not like to change computers, but I love to upgrade software! Maybe this is probably because I am in the software business, but one thing is for sure, having at my reach the most ancient computer and the latest drilling software makes me feel that I have the best of both worlds.

People Should Fall in Love with Their Eyes Closed

Advertising does have impact on people’s purchase decision. Recently, I saw quite a few TV commercials on Perrier bottled water, which shows a scene in a hot summer day. Everything is melting and a lady catches the last bottle of Perrier water before it falls into a swimming pool.

On Saturday, I bought 4 big bottles of Perrier water because the store was selling 4 bottles for $5. This year’s Labor Day was on Monday. It was so hot that I was totally soaked in sweat only after a dozens of minutes doing yard work. It was refreshing to enjoy the big bottle of Perrier water, sitting in the shade. While feeling the tiny bubbles bursting on my tongue, I studied the top and bottom labels, just to make the time in my hands useful.

Suddenly, I noticed a hand-written type of sentence on the back side of the bottom label, which read the title of this article. I was delighted. The pleasure of finding this secrecy and reading this sentence was more than that of drinking the water. How nice it is to have thirst quenched and emotion excited at the same time?! Maybe that is exactly what the bottling company designs. I was wondering.


I admire the idea. We, as drilling engineering software developers, often do something similar on the graphic user interface (GUI) of our software. For example, users can use “Well Path” functions in our Dr. DE (drilling engineering toolbox software) to design different well trajectory.  For example, user can easily create a build-and-drop shape. Dr. DE performs the calculation and displays the results in one click.

Well Path: Build-and-drop: finding maximum inclination | Dr. DE of Pegasus Vertex, Inc.

The tabulated numbers may be too abstracted to many users. So, we have this window of explanation.

Description in Dr. DE - Drilling Engineering Toolbox | Pegasus Vertex, Inc.

It is not quite insightful as the title of this article, but it visualizes the table, just as the sentence elevates the sensation.

We are making our software sophisticated yet simple to use. By doing so, not only do we liberate drilling engineers from problems, but also bring smiles to their faces.