Knowledge and Diderot’s Philosophy

Posted on October 28, 2014 by Freddie Ruiz, PVI

There are three principal means of acquiring knowledge... observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination.
Denis Diderot (French Philosopher)

Knowledge is defined as a familiarity, awareness or understanding of someone or something, for instance the facts, information, descriptions, or skills, which is acquired through experience or education by perceiving, discovering, or learning of a subject.

In the past century technology went through many advances giving knowledge the opportunity to be more accessible to humanity. For drilling technology, literatures, books, computer programs and other sources have been put together by the brightest minds of drilling professionals; however while this technological know-how has notably driven the industry forward, some individuals are at times overwhelmed by the vast amount of information they receive from different sources of media.

The internet is loaded with drilling engineering information, but this information is scattered around in such a way that can lead to generate different answers to just one question.

The demand has been to create an all-in-one type of information and knowledge base software; a digital toolbox that is quick-to-access, reliable, accurate and interactive among other things. For this, PVI has developed a comprehensive collection of drilling engineering tools in a simple-to-learn and easy-to-use software package - Dr. DE.

The software covers more than 180 functions ranging from the fundamentals of drilling engineering to an advanced well path design and 3D visualization of the wellbore; a resource made for every drilling engineer and technician to get the job done right while also making their engineering and sales efforts easy and efficient.

Dr. DE’s engineering features include:

Daily used drilling engineering problems and solutions
Extensive and expandable tubular, centralizer and fluid database
Survey data up to 5000 points
3D wellbore visualization
Intelligent 2D well path design
Detailed illustrations
Support fraction input of tubular sizes

In the beginning of the article we quoted from Dennis Diderot, a person who strongly believed and promoted that all humans have the right to acquire knowledge because it’s in our nature to learn and that the best way of acquiring it, is through experimentation and the exercise of reasoning. With this in mind is how we developed Dr.DE and how our fellow drilling engineers and technicians can benefit from using it to accomplish their daily tasks.

Complaints About Your Job? See This Then!

Posted on October 14, 2014 by Gefei Liu, PVI

It’s the last week of September and we are in Calgary, the energy center of Canada. 2 weeks ago a sudden snow struck the city and killed quite a few trees. We can feel that winter is coming slowly into this growing city, both vertical and horizontally.

In 2012, Calgary added to the city its tallest building, “The Bow”, which is 779 feet. From outside, it is a beauty of steel and glass, no sign of concrete whatsoever. This is what we saw the other day when we visited our clients.

From the picture you can see the cleaning crew hanging way up in the air while cleaning the windows. They are probably trying to get the job done before the winter fully arrives. I think there are lots of people that are afraid of heights, so those people must to a certain degree, like such risky jobs, but personally I feel blessed to be able to walk on solid ground and appreciate the job I have.

It is fair to say that none of us have the perfect job. We make tradeoffs here and there and try to have a balance between what we have and what we want. We develop drilling software and this task requires intensive coding. Occasionally, I lose myself in the midst of numerous lines of programming codes and feel like the purpose of the work gets a little fuzzy. Trips like this one help me see how lucky we are and how much we already have and the chance to meet our users is always a plus. Nothing beats to see how our drilling software helps drilling engineers on their daily tasks.

Do I complain about my job? I try not to. Living in a real world, we all have different jobs. The perfect job does not exist because each of us has our own definition of it and even if it does exist, somebody else has it. Maybe the perfect job cannot be found, but is created through a combination of harnessing our potential that not only increases our performance, but brings us more job satisfaction.

We Wear The Watch We Make

Posted on October 1, 2014 by Gefei Liu, PVI

I am not just one of our software developers; I am also a user and so is everyone else on our team. Our insatiable curiosity and passion about drilling engineering and problem solving are the driving force behind delivering our products. Our goal is to save drilling professionals’ time and reduce risks, and if we do it right, we also help ourselves – BONUS!

Software development, specially drilling software development, requires collaboration from a pool of talents, ranging from drilling engineers, mathematicians, programmers and quality control personnel. A good software package is measured not only by the accuracy or comprehensiveness, but also by how easy it is to use it. The gaps between users and developers are always there. We try to bridge that gap by utilizing our own software on our consulting projects.

Using our own software transforms us from developers to decision-makers. We become more sensitive to users’ needs and more careful in our interface design.

It is not always easy, but it is a lot of fun. From every interface design we put into the software, we toss aside dozens more. If we are complaining about the number of clicks to accomplish a task, then the users would too.

The results?

The software we use is the software we develop, in other words, we wear the watch we make.

An Illustration and A Twisted Finger

Posted on September 23, 2014 by Freddie Ruiz, PVI

Let’s illustrate in an easier way what torque and drag is:

Hold your index finger tightly in the fist of your other hand.

Now twist your finger.

Do you feel how your finger does not want to twist?

Yes!

You know why?

Because it's not built to be twisted.

The pain you feel is because of the torque you are putting on the joints. - That's torque.

Do you feel how your finger resists the pull because you have a good grip on it with your fist? - That's drag.

Torque and drag can have a dramatic increase in horizontal and extended-reach wells and can become the limiting factor in determining the horizontal length or extended-reach of a well. For this reason, precise calculations of torque and drag are necessary for drilling operations. Torque and drag are the results of friction caused by a moving pipe inside the wellbore: torque occurs when rotating the pipe along the wellbore and drag occurs when moving the pipe.

When drilling horizontal or extended-reach wells, excessive torque and drag may become troublesome both in the drilling operations and later in the completion operations. Estimating torque and drag is very important, but the calculation of drag in the build section of a well is complicated by the effect of the axial force (tensile or compressive) on the lateral contact force which produces the sliding drag and in turn causes changes to the axial force itself. The axial force has a great effect on the torque and drag calculations in the build section. When the axial force (tension or compression) becomes large enough to let the pipe contact only one side of the wellbore, the torque and drag in the build section will increase proportionally with the increase in the axial force.

The most common way to calculate approximate torque and drag values in the build section involves monotonous numerical calculations: dividing the build section into many small pieces, assuming the axial force remains constant in those small pieces, calculating the friction factor for each of the pieces, and then summing these values to get the total drag over the entire build section. This process is both time-consuming and difficult for field engineers.

The analysis of torque and drag is made easier by today’s technology. There is a comprehensive torque and drag software in the market that removes many of the risks during the drilling process. This software was developed by PVI and it’s called TADPRO (Torque and Drag).

This software comes with features that help users to:

Calculate hookload and surface torque
Identify potential buckling
Perform sensitivity analysis
Determine side force
Analyze forces downhole
User-friendliness and graphical outputs

Illustrations have always been a great learning method and today we have learned two things:

Fingers were not made to be twisted.
Likewise a pipe is not built to be twisted, but the torque and drag inevitably occurs during horizontal drilling, but with the help of TADPRO, torque and drag can be calculated and predicted, therefore the risks are reduced.

A Phrase of Being Stuck

Posted on September 17, 2014 by Freddie Ruiz, PVI

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:

Differential pressure pipe sticking
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

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.

Like The Barriers on The Road

Posted on September 9, 2014 by Freddie Ruiz, PVI

This is a story about a town located at the bottom of a deep valley.

The only road into town was steep and windy, barely hanging on to the steep mountain-side surrounding the town. Very often, cars traveling into town would get too close to the edge of the road and tumble into the valley. Over time, the town spent hundreds of thousands of dollars responding to wrecks and they got tired of going out to respond to the same thing over and over. The town’s people rendezvoused to discuss the matter and how to solve it. Some folks thought they should ignore what was happening and let people fend for themselves. Others thought they should continue to help the people who went off the road, but should charge them for the costs involved. A few suggested that they should just close the road so those strangers wouldn't cause them any more problems. The majority of the people quickly acknowledged that the road posed a risk for strangers but also for friends, family and the townspeople themselves. Since nobody agreed to a specific solution, one person suggested they put up a barrier on the edge where cars most often went off the road and everybody agreed and so they did. Over the years, the barrier cost the community far less than all the rescuing they had been doing for so many years. A simple barrier was the solution.

It's a simple story, but a great metaphor for prevention. Like the barriers on the road, for more than 6 decades, casing centralization has been established as being essential to efficient mud removal and therefore to a successful cementing job. Prior to a production it is very common for field engineers to spend time improving casing centralization using software, particularly for highly deviated wells. However today, while long lateral wells are being drilled, they become more challenging in getting the casing to bottom and achieving good zonal isolation. That is why casing centralizers play a key role in achieving these objectives and should be evaluated differently than they have been in the past.

Predicting casing standoff is essential since not knowing where to locate the centralizers and how many are needed can cause several problems. The main reason for centralization is to ensure a uniform distribution of cement around the casing. No centralization or poor centralization will cause channeling of the cement and therefore produce poor cement adherence.

What do centralizers prevent?

When running a casing, the adequate use of centralizers reduces the chance of wall sticking.
In deviated wells because of the increased amount of support, the casing requires to stay in the center of the hole – especially in build-up sections - a more dense distribution of centralizers is required than in straight holes.

There are two main types of centralizer:

Spring (Bow) Centralizers
Rigid Centralizers

Spring (bow) centralizers are often used for vertical and deviated wellbores and rigid centralizers are used for horizontal wellbores. The method of installation for both of these depends entirely upon the centralizer design. However, care must be taken to ensure the quality of the cementing job. Centralizer placement is synonym of prevention.

For this PVI developed CentraDesign software that optimizes the centralizer placement, predicts casing standoff and torque and drag for extended reach drilling and deviated wellbores.

CentraDesign also determines the number and placement of centralizers, hence providing both service companies and operators with a very sophisticated yet easy to use tool that will help prevent problems during the cementing process.

Prevention is like the barrier put up to keep cars from going over the edge and it works to keep unwanted things from happening in the first place.

The Risk of Not Keeping Risks Under Control

Posted on September 2, 2014 by Freddie Ruiz, PVI

American writer and best-selling author Denis Waitley said:

“Life is inherently risky. There is only one big risk you should avoid at all costs, and that is the risk of doing nothing.”

Risks are everywhere. I was watching a documentary on earthquakes and hurricanes and it got me thinking about how there are risks in everything that surrounds us, but that doesn’t stop us from improving and moving forward. We have to acknowledge that risks exist. Taking risks is in our human nature and when something goes wrong we work towards being more prepared in the future.
Some people are reluctant to take risks because they’re somewhat afraid, but the reality is that taking risks can:

Open people up to new challenges and opportunities.
Empower people to establish new limits in their minds.
Stimulate people to become more creative.
Result in positive outcomes.
Help people to clearly define what they’re trying to achieve.
And once they have become accustomed to taking risks, they break free from the average way of thinking.

In the drilling industry every step and every decision has to be made, yet it is necessary to drill for oil. As a nation on the wheel, the usage of petroleum has become an everyday thing not only for the United States but for the rest of the world as well. So basically it’s all about risk control for every aspect of life including the drilling industry, and in this case it is all about a well done cementing job.

For drilling engineers, cementing seems to be more of an art than a science or technique. Cementing is the process of displacing cement to the annular space between the well-bore and casing or to the annular space between two successive casing strings. With the latest technologies and analytical software such as CentraDesign and CEMPRO developed by PVI, cementing engineers can use these types of software to ensure a complete and proper cement displacement.

A successful cementing job is one of the most important factors in the productive life of any well. However, challenges are always coming along as the wellbore goes deeper and to the places that are harder to reach. It’s already prevalent to predict a cementing job by computing the downhole temperature and pressure. If the cementing job is well done, all the risks are under control; a longer life of the wellbore and a higher productivity is promised.
We are living in a world where technology is advancing quickly. As PVI developers we are trying our best to develop more advanced software to meet the new needs. That’s why we developed CEMPRO⁺, the ultimate enhanced version of PVI’s mud displacement model, CEMPRO^®.

Designed for land, offshore, conventional and/or foamed operations, CEMPRO⁺ uses advanced numerical methods to solve momentum and continuity equations on 3D grids and calculates the fluid concentration as well as the displacement efficiency. It accounts for many factors that can affect the efficiency of displacement jobs, including fluid properties, pumping rates, casing standoff and complex wellbore geometry.

Although taking risks requires some blind trust in most cases, with a well done cementing job, drilling does not need to be a problem, but the complete opposite. We’ll never know what we can accomplish until we take the risks, and we can always get the best rewards by finding the right solutions or tools to keep the risks under control.

Looking for The Right Key

Posted on August 26, 2014 by Freddie Ruiz, PVI

“Many people are confused with complexity and shy off from it. Strangely, complexity arises from simple rules, but people are finding it difficult to grasp. However, you need to move out of this situation soon before it gets out of control. Do what ants do: they diverge to look for new sources of food and then converge once a new path has been identified. Look for new ideas till you identify a new path or a new pattern to help you find the right key for the right lock that opens up the right door.”

- Ali Anami

As the 21^st century passes, the oil industry continues to look for new ways to innovate and increase its productions. It continues to search for reserves in more complex environments, especially in deep water. Already many fields are slated for development in both shallow and deep offshore wells and new solutions and technology are needed to meet these goals.

As a reservoir depletes, the pressure and production rates decline and lost circulation or differential sticking problems can prevent the drilling operations from increasing their production. Underbalanced drilling (UBD) is a practical method to drill in such depleted or low-pressure areas. One of the many benefits of underbalanced drilling is that it can prevent or reduce near wellbore permeability damage; as a result, it enhances the production, delaying water, gas or oil leaks due to the lower pressure drop that is required for the same flow rates.

The advantages of Underbalanced Drilling are:

Improves drilling performance

Increases penetration rate (ROP)

Extends bit life

Minimizes differential sticking of pipe

Diminishes lost circulation

Reduces formation damage

Simplifies early production while drilling

Allows formation evaluation and tests while drilling

Higher productivity completions

Picks total depth (TD) from inflow performance

Closed, pressure-controlled system

In order to design and achieve a successful underbalanced drilling project many important elements must be taken in consideration and there are 4 steps that have to be applied to determine the options and requirements for UBD: This is particularly important for underbalanced drilling operations offshore from floating vessels, where critical issues can increase significantly.

Determine Bottom Hole Pressure (BHP) requirements.

Identify the drilling fluid options.

Establish the well design and perform flowing modeling.

Select the surface equipment.

An advance software model has been developed which incorporates these elements, including multiphase flow calculations, gas and liquid injection rate optimization, hydrostatic gradient and frictional pressure loss calculations, cuttings transport, reservoir fluid influx (oil, gas, or water), and operational procedures such as tripping and liquid unloading.

Just like the rest of PVI's software, UBDPRO is the right tool when it comes to increasing a well’s productivity. It’s all about looking in the right direction (for the right key) and making the efforts to obtain it.

Hot Game with Hot Model

Posted on August 19, 2014 by Gefei Liu, PVI

A couple of days ago, at 3:30pm, the hottest time of the day, my friend Francisco and I played a match of outdoor tennis for an hour and half, under the unforgiving sun of August and high humidity of Houston.
For the first 30 minutes, I felt great. Then, my legs were not coordinating with my mind. I only won 4 games in 2 sets. But I was proud of myself to be able to survive the heat.
We took breaks and chatted between games. During one of the breaks, while holding his hot iPhone, he shook his head and told me: “You know what, my phone quits working!” Then he read to me the message on his cellphone screen, which said:

Fig.1: HTHP Classification

We started laughing and felt good about ourselves: we were running directly under the sun and the iPhone was sitting in the shadow of the pavilion.

Heat does amazing things to our bodies, helping us warm up or exhaust us. It was my intention to test the strength of my body when exposed under the sun. It was not my best experience, but it served a purpose.

In petroleum industry, the days of easy, cheap oil are over, making it harder to meet demands without any complicated and expensive projects. As operators continue to drill in deeper and more extreme formations, we are facing extreme temperatures, which create detrimental effects to drilling operations.

More often than not, we encounter high temperature and high pressure (HTHP) conditions, which are defined with the following picture.

Fig.2: HTHP Classification

HPHT is currently defined as 20,000 psi and 450°F and ultra-HPHT is typically considered anything above.

When drilling a well, we use drill pipes and other tools including downhole motors, which have rubber parts. The combination of high temperature and pressure, and other tough conditions has a dramatic effect on reducing the drilling tools’ ability to withstand the HPHT conditions. When exposed to high temperatures for extended periods, the rubber parts may deteriorate, causing operational failures. High temperatures also have implications for flow assurance (wax, hydrates, or viscosity), stress analysis, drilling tool temperature tolerance, completion fluid density and cementing, etc.

If we can predict downhole temperatures, we can evaluate the risk involved. The downhole temperature changes as we start the mud circulation bring heat from formations at the bottom of the hole upward and release the heat to cool down the formation in the upper section of a well. Here is a snap shot of a temperature profile in a wellbore, using CTEMP, PVI’s Wellbore Circulation Temperature Model.

Fig. 3: CTEMP - Temperature Profile Along the Wellbore

Predicting the temperature and knowing our limits are necessary for tennis games and drilling operations.

From The Pencil to Engineer Is Human

Posted on August 12, 2014 by Freddie Ruiz, PVI

“Design is a way of life, a point of view. It involves the whole complex of visual communications: talent, creative ability, manual skill, and technical knowledge. Aesthetics and economics, technology and psychology are intrinsically related to the process. Design is the evolution of useful things.”

- Paul Rand, also known as the American Modernist.

When Paul Rand made this comment he was referring to two books written by Henry Petroski: The Pencil and To Engineer Is Human, in which basically he talks about how we can take everyday objects and turn them into better useful objects. For instance, how pins were turned into paper clips; how Styrofoam containers evolved; how Post-it Notes came about and even how a simple rock can be turned into something very useful. The list goes on and on, and it is easy to understand the connection between Petroski’s points of view with Rand’s ideas on invention, innovation and ingenuity.

When it comes to the evolution of useful things, the oil and gas industry has many examples, but just let’s take this moment to talk about one of them: cementing and its development process.

Cement fills and seals the annulus between the casing string and the drilled hole. It has three general purposes:

Zone isolation and segregation
Corrosion control
Formation stability and pipe strength improvement.

Cement forms a very strong and impermeable seal from a thin slurry. The properties of the cement slurry and its behavior depend on the components and the additives in the cement slurry.

The cement is produced from limestone and either clay or shale by being roasted at 2600 to 3000°F. This high temperature fuses the mixture into a material called clinker cement. Once the roasting step is done, the rough clinker product is ground to a size specified by the grade of the cement. The final size of the cement particles has a direct connection with how much water is required to make the slurry without producing an excess of water at the top of the cement or in pockets as the cement hardens. However, not all cements, including those made from the same components, will have the same reaction when mixed with water. Generally, the differences are in the quality of the grind of the cement, impurities in the water and in the additives added during the cement manufacturing process.

The design and test of the slurry are essential parts of every cementing job and without an efficient lab database cementing companies can face many problems, but thanks to the evolution of technology PVI has developed the right tool for this: CEMLab (Cement Lab Data Management).

Since its first release in the fall of 2012, CEMLab has evolved into a powerful web-integrated and highly functional software product. CEMLab formulates slurries, calculates the amount of all ingredients, generates weight-up sheets and lab reports and allows engineers to have quick access to all their slurry formulation, and testing statuses anytime from anywhere. These are just a few of the many features that make up CEMLab. Just like from the books “The Pencil” to “To Engineer Is Human” we get to see how an object can be designed and turned into something more useful and successful, CEMLab has been turned into a useful, successful and sophisticated lab tool.

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