Return to Square One: A Round Trip without Reaching the Destination

Due to business, I had to make a trip to Saudi Arabia via Paris. It was uneventful from Houston to Newark, where I made connection. I boarded on the flight, the meal was delicious and I took a Benadryl, hoping I could get some sleep on the way to Paris.

While I dreamt, I heard the announcement, “Ladies and gentlemen, as we start our descent…” I woke up and was delighted to imagine that I would be in Paris in a few minutes. Looking at the lights below, I tried to locate the Eiffel Tower. Then, a suspicious feeling arose, it was too soon for us to arrive; we should land in Paris during the day time. Then I heard my neighbor, who had also just woken up, saying, “Why are we landing in Newark?”

Finally, a flight attendant told us that 3 hours after the airplane took off, as we were just above the Atlantic Ocean, they found some issues with one of the engines. The captain decided to return home. The following is our flight trajectory that night.

Although I am a frequent business traveler, this was my first time experiencing this. I had a meal in the air, took a nap, and then I was back to square one. After all, the airline company must have had its own justification to fly back, and it is better to be safe than sorry.

As a result of this incident, except extra fuel cost, the airline company had to pay for our hotel and meals during delays. Apparently, everyone in this trip lost 6 hours; moreover, it brought about much inconvenience. No one would enjoy these types of surprises. However, the big picture is that the decision on flying back may have saved hundreds of lives. I am certain that airlines are making efforts to ensure flight safety and punctuality.

Drilling operations are like flight missions. There is a destination we want to reach, which we call total depth (TD). We assemble drill pipes, tools and bit. We circulate drilling fluid, control the hook load and weight on bit (WOB) to penetrate. But things could go wrong: pipe may get stuck, circulation lost, or bit dulled. Like this trip, those problems are unpredictable.

What we can do is to engineer the operation more carefully to identify potential problems prior to drilling. With our best effort, we keep the problems under control, and then we can be at ease with the outcome.

Despite the cancelled flight, I had brief but good sleep in a hotel by the airport. The next night, I caught another flight. After dinner, I took another Benadryl. This time, I woke up in Paris!

A Phrase of Being Stuck

Jill Scott said:

“I need to find a creative diversity because if I get stuck, I get unhappy.”

At times we all find ourselves stuck in different aspects of our lives.  Maybe not for the same reason; sometimes it could be fear, guilt, nostalgia and even boredom, but the result is the same.

We’re stuck.

But then, how can we get out of it? How do we get unstuck? The answer is very simple: “we find the problem and along with it, we find the solution”. Let’s take this example and apply it to the drilling process.

During a drilling operation, if a pipe cannot be freed from the hole without causing any damages to the pipe and without exceeding the drilling rig’s maximum hook load this is considered a stuck pipe. Pipe sticking can be classified under two categories:

  1. Differential pressure pipe sticking
  2. Mechanical pipe sticking

When having complications due to a stuck pipe this can be nearly half of the total cost of the well, making stuck pipe one of the most expensive problems that can occur during a drilling operation and is a serious risk in high-angle and horizontal wells.

Drilling through depleted zones, where the pressure in the annulus surpasses that in the formation, might cause the drillstring to be pulled against the wall and embedded in the filter cake deposited there. The internal cake pressure diminishes at the point where the drillpipe contacts the filter cake, causing the pipe to be held against the wall by the differential pressure. In high-angle and horizontal wells, the gravitational force contributes to prolonged contact between the drillstring and the formation.

What are some of the mechanical causes for stuck pipe?

  • Keyseating
  • Packoff from poor hole-cleaning
  • Shale swelling
  • Wellbore collapse
  • Plastic-flowing formation (i.e., salt)
  • Bridging

What are some of the signs that need to be monitored to prevent stuck pipe?

  • Increasing in torque and drag
  • Excessive cuttings loading
  • Tight spots while tripping
  • Loss of circulation while drilling

Depending on what the suspected cause of sticking is, it is necessary to act properly and urgently.

There is a tool developed by PVI Called StuckPipePro, which is a stuck pipe analysis that every operator should have to reduce the risks of pipe sticking to the minimum. This effective tool is equipped with great features, for example: stuck chance calculation, free point calculation, back-off force calculation, stuck pipe mechanism, which assist in determining the mechanism that is actually behind the stuck pipe situation and which technique should be used to free the pipe. It also comes with a decision flow chart that guides users through a series of questions to find the cause of pipe sticking.

StuckPipePro - Stuck-pipe-analysis

StuckPipePro - Stuck Pipe Analysis

Just like the phrase of being stuck said by Jill Scott; once we find the problem, we’ll find the solution, in this case, with StuckPipePro.

5 Benefits of Drilling Software Training

These days software, in general, becomes more and more user-friendly, even as it gets more and more sophisticated. We, as users, also have more confidence in using software without being bothered to read manuals or attend training sessions. Our busy schedules do not allow us to attend software training.

The situation is the same for drilling software users. As drilling engineers, whether we work in oil companies or in service companies, we always have next wells to drill, meetings to attend and deadlines to meet. We are so busy focusing on output that sometimes we forget about taking the time to receive input and recharge ourselves.

Unlike MS Office, drilling engineering software is not general-purpose software. It requires more specific knowledge to obtain results and understand the meanings of those results. Drilling software training should always be the first step to effectively use a software.  Here are the reasons why software training is necessary:

1. Understand the engineering models

All drilling engineering software is based on certain mathematical and engineering models. Understanding these models behind the graphic user interfaces helps us acknowledge the limitations of the software as well as the capabilities.

2. Interpret data meaningfully

Drilling software needs input data such as survey, BHA, wellbore and mud properties to predict hook load, pump pressure and ECD, etc. Like other software, only meaningful input data can lead to meaningful output data. It is necessary for users to know what the required input data is and to explain the meanings of the output data and charts to their colleagues or clients.

3. Increase efficiency

Training helps potential users to see the big picture as well as the tricks and features of the software. Once users know more aspects of the drilling software, they can use the software more efficiently. For example, survey data is essential to describe the well path and calculate the torque, drag and hydraulics. Survey data can be in various formats, Excel, text or PDF. All of our software can import data from these formats. The survey import feature saves tremendous time, especially when importing survey data from a PDF file.

4. Gain confidence

Software training connects the users with the developers of the software. The 2-way communication helps the users understand the ideas and structures of the software. Once users understand the inside calculations, the software is no longer a black box to them. Training removes the mysterious veil of the software. Users become more confident on explaining the results to clients.

5. Guide and influence

The software development training also provides a platform for users to influence and even guide the software development. Users, involved in field operations, can give suggestions, which can enhance the functions. This leads to better versions and win-win situations for software vendors and users.

Ancient Chinese philosopher Confucius once said:

“I hear and I forget.

I see and I remember.

I do and I understand.”

How true this is to drilling software training.

Merchant of Venice and Hook Load

I visited Venice after this year’s SPE/IADC Conference in Amsterdam in March. During that week in Venice, I stayed in a quiet world: no automobile, no motor cycle or train. You can simply add “water” in front of the names of our ordinary transportation to describe the local means of moving around: water-bus, water-taxi, and water-gondola.


While enjoying the Italian cuisine and limoncello, I suddenly thought of one of the famous play of Shakespeare’s: Merchant of Venice. The story with Venice as the venue goes like this.

A Venetian merchant Antonio has a friend Bassanio, who is desperately in need of money to court Portia, a wealthy heiress who lives in another city. Without enough money, Bassanio and Antonio finally secure the loan from Shylock, a Jewish moneylender, with Antonio as the loan’s guarantor. Shylock hates Antonio, but acts agreeably and offers to lend Bassanio three thousand ducats with no interest. Shylock adds, however, that should the loan go unpaid, shylock will be entitled to a pound of Antonio’s own flesh, to which Antonio agrees.

Later in story, news comes that Antonio has lost his ships, and that he has forfeited his bond to shylock. Shylock ignores the many pleas to spare Antonio’s life, and a trial is called to decide the matter. Portia, his friend’s fiancée, disguises as a young man of law and asks Shylock to show mercy, but he remains inflexible and insists the pound of flesh is rightfully his. Portia examines the contract and, finding it legally binding, declaring that Shylock is entitled to the merchant’s flesh. Shylock ecstatically praises her wisdom, but as he is on the verge of collecting his due, Portia reminds him that he must do so without causing Antonio to bleed, as the contract does not entitled him to any blood. Trapped by this logic, Shylock hastily agrees to take Bassanio’s money instead. The ending of the story has more drama.


We live in a world of measurements. Measurement is a cornerstone of engineering and science. For some reason, the story in my memory is that Portia reminds Shylock that he has to cut exactly one pound of Antonio’s flesh, not even one ounce more or less.

In drilling industry, we have mud weight (ppg) to measure the density of drilling fluid, pipe weight(lb/ft) to represent the thickness of pipe with given OD. The weight indicator - hook load is the total force acting (pulling down) on the hook on the rig.

Hook load is one of the few important readable operation parameters on rig floor. It’s basically the total force includes those of traveling assembly weight, buoyant pipe weight in a deviated well plus or minus the frictional drag caused by pipe movements inside borehole. Torque and drag (T&D) software such as TADPRO serves the purpose of predicting hook load, surface torque and other variables for drilling and tripping operations.

We can calculate hook load and surface torque precisely if we know all the details downhole. However, the uncertainties downhole, such as open hole sites, survey accuracy, make the prediction exactly match rig floor reading unlikely. This does not discount the importance of hookload prediction, because the significance of T&D calculation is its trend.

The following picture shows the hook load changes as we drill to TD. The hook load is increasing at beginning (due to longer pipe into the hole) and decrease later as we drill into build-up and horizontal sections (more drag).

Hook Load Predicted By TADPRO | Pegasus Vertex, Inc.

Hook Load Predicted by TADPRO

Eventually, the hook load is approaching zero. This indicates that the pipe weight in the vertical section will not be enough to overcome the frictional drag resulted from the horizontal section: a problem associated with horizontal and extend-reach well drilling.

A pound more or less on this curve is not as important as the trend, which signals us what will happen according to our planning.

Drilling Software: A Bridge between Research Efforts and Field Executions

The term R&D or research and development refers to a specific group of activities within a business. There are 2 main goals of an R&D project: develop new products and discover/create new knowledge.

In our drilling community, we have seen many R&D projects with various sizes and duration. Petroleum engineering departments of many universities receive grants from industry and conduct specific tasks. On a big scale, joint industry projects (JIP) gather resources from different companies, both operators and service providers. I was involved in some big JIP projects such as DEA-44 (Horizontal Technology), DEA-42 (Casing Wear Technology) etc. By the way, DEA here stands for Drilling Engineering Association, not Drug Enforcement Administration. Many R&D projects produce great know-how and sometimes prototype products. However, we need a vessel to package the knowledge from these R&D efforts.

Software naturally becomes the form to hold the knowledge. With graphical user interface (GUI), it can become a powerful tool for end users, who often are not involved in the project.

An R&D project without action is incomplete. A software package serves as a bridge between the gap of research results and field executions. For example, not many people understand how the equation of force balance is used to calculate torque and drag along a drill string or casing, but most drilling engineers understand the hook load and surface torque charts. As a matter of fact, we don’t have to be able to solve numerical equations to be drilling engineers. The advanced engineering and calculation capabilities are already packed in the ready-to-use software like TADPRO (torque and drag model).

If not for exercising purpose, you probably want to ride to office than walk. You probably want to take bridge than take boat to reach the other end.

Let our drilling software help you drill more efficiently.