7 Basic Ideas

In completion of oil and gas wells, cement separates the wellbore, prevents casing failure, and keeps wellbore fluids from contaminating freshwaters. The basic factors engineers and operators must consider for successful cementing jobs are summarized in seven basic ideas:

  1. Condition the Drilling Fluid
  2. Use Centralizers
  3. Move the Pipe
  4. Increase the Displacement Rate
  5. Design Slurries for Proper Temperature
  6. Select and Test Cement Components
  7. Select a Proper Cementing System

1. Condition the Drilling Fluid

The drilling fluid condition is the most important variable in achieving very good displacement during a cementing job. As the workers pull the drill pipe, run the casing, and prepare for cementing operations, the drilling fluid in the wellbore basically remains static and hardens. Pockets of mud commonly exist after a wellbore is drilled and they make displacement difficult. These pockets of gelled fluid must be broken up. Regaining and maintaining good fluid mobility after running the casing is essential.

2. Use Centralizers

Centralizers are effective mud displacement helpers. Centralizers make easier the removal of gelled-mud and allow better cement bond with the wellbore. Centralizers are designed to serve various needs, for instance, they help with well control, provide increased mud-removal benefits, optimize drilling-fluid displacement. When a casing is poorly centralized the cement bypasses drilling fluid by following the path of least resistance. Good pipe standoff helps ensure uniform flow patterns around the casing. Centralizers also change fluid flow patterns and promote better mud displacement and removal.

3. Move the Pipe

Moving the casing before and during cementing breaks up the gelled pockets and it loosens the cuttings trapped in the gelled mud. Pipe movement allows high displacement efficiency at lower pump rates by keeping the drilling fluid flowing.

Movement compensates partially for poorly centralized casing by changing the flow path and allowing the slurries to circulate completely around the pipe. In some instances, some liner hangers and mechanical devices prevent casing movement, which must be considered during the cement displacement design.

4. Increase the Displacement Rate

High-energy flow in the annulus is more effective in ensuring good mud displacement. Turbulent flow around the casing circumference is desirable, but not necessarily essential. The best cementing results are obtained when the spacers and cement are pumped at maximum energy, the spacer is appropriately designed to remove the mud, and a more proficient cement is used.

5. Design Slurries for Proper temperature

Operators can optimize the slurry design if they know the actual temperature the cement will encounter. Bottomhole cementing temperatures affect the slurry thickening time, set time, rheology and the compressive-strength development. Operators tend to overestimate the amount of materials required to keep cement in a flowing for pumping, which can result in unnecessary cost and well-control problems. They can optimize cost and displacement efficiency by designing the job on the basis of actual wellbore circulating temperatures, obtained from a downhole temperature sub recorder.

6. Select and Test Cement components

Operators are encouraged to design cement slurries for specific applications, with good properties to allow placement in a normal period of time. The ideal cement slurries have no measurable free water, provide adequate fluid-loss control, have adequate retarder to ensure proper placement, and maintain a stable density to ensure hydrostatic control.

Before performing the job, they should check the cement reaction and actual location mix water to ensure that the formulation will perform as it is expected. Contaminants in the mix water can produce large variances in thickening time and compressive strength.

Organic materials and dissolved salts in mix water can affect the slurries setting time.

Cement dehydration from the loss of filtrate to permeable formations can cause bridging and increased friction pressure, viscosity, and density. Pump pressures can increase and additives can be used to provide fluid-loss control when is necessary to compensate for dehydration.

7. Select a Proper Cementing System

Operators select cement systems based on job objectives and well requirements.

Cement is basically inflexible. Cementing systems are similar in many ways, but sometimes they vary, for instance, in their capability to provide good zone isolation in changing environments. The cement selection has always been on the basis that higher compressive strengths result in higher cement sheath quality. Research has proven that the ability of cement to provide good zonal isolation is better defined by other mechanical properties. Good isolation does not necessarily require high compressive strength. The real competence test is whether the cement system in place can provide zone isolation for the life of the well.

For all these situations PVI has developed a series of software such as:

CentraDesign - Centralizer Placement Software

CentraDesign - Centralizer Placement Software

MUDPRO - Drilling Mud Reporting Software

MUDPRO - Drilling Mud Reporting Software

StuckPipePro - Stuck Pipe Analysis Software

StuckPipePro - Stuck Pipe Analysis Software

that can help engineers and operators to perform a better quality job and avoid any potential problems that can put at risk the production.

A New Drilling Engineering Toolbox App

Every drilling engineer and technician knows that performing drilling engineering calculations can be a tedious and time-consuming process, considering the many researches they have to do in order to find the right results. At times, even these results are not quite exact. While technology has tremendously driven the oil and gas industry forward with the creation and development of advanced software, most of the time these are meant to be used in the office and are not so simple and portable. To assist with this issue, Pegasus Vertex, Inc. has launched the new DR.DE Lite mobile app for both Android and Apple devices. This free app was developed to provide drilling engineers and technicians with a simple, useful, paperless and portable tool to make their drilling engineering calculations easier and faster.

Dr.DE_Lite_Mobile_AppThe DR.DE Lite app is equipped with 29 functions that are divided into 11 groups.

Dr.DE Lite App: 11 GroupsFrom this great selection of functions, this tool can help you save time and efforts to get the calculations you need. In the past, drilling engineers and technicians had to obtain the information from different sources and after gathering the information manually perform the calculations and that could take up to an hour; however, now it can be done in a matter of seconds and the results are precise.

In this new tool, every function comes with three main buttons: Default, Clear and Calculate. The “Default” button gives users an example of standard input data. The “Clear” button allows users to delete all input data and the “Calculate” button performs the calculations based on the data users enter. The app collects all the information the users provide and in case the wrong data is entered, it will give a message as a warning.

For example, the “Hydraulic’ group contains four sub-functions: 1. ECD, which calculates the ECD at depth. 2. Hydrostatic pressure, which calculates the hydrostatic pressure of the mud column in a deviated well. 3. Pressure drop (Bingham) annulus, which calculates the pressure drop in an annular section for Bingham plastic fluids. 4. Pressure drop (Power law) annulus, which calculates the pressure drop in an annular section for power-law fluids.

Dr.DE Lite: Pressure DropIn the “Pressure drop” function, users can specify the wellbore configuration, as well as fluid properties and flow rates. DR.DE Lite performs calculations for fluid velocity, flow pattern, pressure drop, Reynolds number and other key parameters for different flow patterns.

The DR.DE Lite app is the perfect tool that complements your work. It’s easy to download, easy to use, very convenient and free. To download DR.DE Lite, scan the QR code or download the app from your mobile play store.

Dr.DE_Lite: Free Drilling Engineering Toolbox Mobile App

Calculation and Prediction

The pulling and running of pipe causes pressure surges and the prediction of these is a matter of economic importance in wells where the pressure has to be maintained within narrow limits to prevent formation-fluid influx and lost circulation. When these types of situations occur, the drilling engineer needs the best possible method of calculating and predicting surge pressures to drill these wells with a minimum of risks.

Pressure surges have been known for a very long time to cause well-control problems. For instance in 1934, pressure surges were identified as a result from pipe swabbing the possible cause of fluid influx, and in worst cases, blowouts. Also In 1951, positive pressure surges were measured and linked to lost-circulation problems.

For most wells, the extent of the pressure surges is not critical when the proper casing design and mud programs leave large enough margins between fracture pressures and formation-fluid pressures. However, a certain fraction of wells cannot be designed with large surge-pressure margins and in this situation the pressure surges may still be a concern.

The need to predict pressure surges in critical wells is the reason PVI developed SurgeMOD.

SurgeMOD - Surge Pressure Prediction SoftwareWith this surge and swab pressure prediction model, the annular pressures are calculated to be consistent with frictional pressure drops caused by fluid motion; the drilling mud can be well displaced by the pipe motion. This model is sufficient for an effective use for both drilling and completion. It analyzes the complex downhole hydraulics when running the casing for various pipe conditions and circulation sub tools. SurgeMOD not only predicts the surge and swab pressures for a given running speed, but also calculates maximum running speeds at various depths. After the casing or liner is set, it will calculate the maximum acceptable circulation rate before fracturing the formation.

This surge and swab pressure model shows an excellent agreement with the measurements of surge and swab pressures collected during the field tests. It accurately predicts maximum surge and swab pressures as well as the variation of pressure with time at any position in the well bore. Predicting surge and swab pressures using SurgeMOD can minimize potential problems in a well bore and allow more efficient trip speeds for running or pulling pipe.

Change and its Effects

“Change is a weapon whose effects depend on who holds it in his hand and at whom it is aimed” - Anonymous

With that being said, how can we relate that quote to what we are going to talk about in this article?

Well, changing the mode of a well causes changes in temperature and pressure inside and outside the tubing. This can create length and force changes in the tubing string that can potentially affect the packer and downhole tools. Once the packer is installed and the tubing landed, any operational mode change will cause a change in the length or force in the tubing string.

The length and force changes can be considerable and can cause enormous stresses on the tubing string, as well as on the packer under certain conditions. The net result could reduce the effectiveness of the downhole tools and damage the tubing, casing, or even the formations accessible to the well. Failure to consider length and force changes may result in costly failures during the operations.

There are four factors that tend to cause a change in the length or force in the tubing string:

  1. Piston effect: caused by a change in the pressure in the tubing or annulus above the packer on a specific affected area
  2. Ballooning effect: caused by a change in the average pressure inside or outside the tubing string
  3. Buckling effect, caused when internal tubing pressure is higher than the annulus pressure.
  4. Temperature effect: caused by a change in the average temperature of the string

Piston Effect

The length change or force induced by the piston effect is caused by pressure changes inside the annulus and tubing at the packer. It is possible to get rid of the forces generated on the tubing string by the piston effect by anchoring the seals in the packer bore. All the forces are now being absorbed or contained completely within the packer.

Ballooning Effect

The ballooning effect is caused by the change in average pressure inside or outside the tubing string. Internal pressure balloons the tubing and causes it to shorten. Likewise, pressure in the annulus squeezes the tubing, causing it to elongate. This effect is called "reverse ballooning."

Buckling Effects

Tubing strings tend to buckle only when the internal tubing pressure (pi) is greater than the annulus pressure. The result is always a shortening of the tubing string, but the actual force exerted is negligible. The diminishing in length occurs because of the tubing string being in a spiral shape rather than straight.

Temperature Effect

Thermal expansion or contraction causes the major length change in the tubing. Heated metal expands, and cooled metal contracts. In a long string of tubing with a temperature change over its entire length, if tubing movement is constrained, forces will be introduced as a result of the temperature change.

The direction of the length change for each effect must be considered when summing them. It follows that for a change in the conditions; the movement created by one effect can be offset or enhanced by the movement developed by another effect.

For these scenarios, PVI has developed TMPRO.

TMPRO-tubing movement | PVI drilling software

Among its many features it includes:

  • 3 packer types (free, limited and anchored)
  • Piston, buckling, ballooning and temperature effects
  • Pipe database
  • Different tubing materials
  • Initial and final fluid configurations
  • Tensile and stress strengths
  • Burst and collapse strengths
  • Operation designs

TMPRO is based on the theory developed by Lubinski and Hammerlindi and it’s a great tool to avoid any tubing or packer problems allowing its users to make the right change to have the right effects.

Inward Significance

“The aim of art is to represent not the outward appearance of things, but their inward significance.” - Aristotle

Art is an archetypal creative activity and it requires serious emotional commitment. Engineering is creative in other ways, but it is also considered art.

In lots of ways, the creation of a painting is much alike to the development of a software. Artists have the urge to express their thoughts and ideas. They envision the final result in their minds and step by step they create a work of art. They use all the essential tools to express their abstract vision into an artistic reality.

In a similar way, during the development process of a software, ideas are converted into technical designs that are represented by digital reports, flowcharts and databases in which the developers interpret the abstract formulas and logics into a realistic and tangible tool.

As drilling software developers, we have something to create for our clients, not only because it helps them achieve their project goals but also helps them gain more knowledge on the matter. Just like when creating a painting, each layer of color is a step closer to the final piece, when we are developing our software, every idea, thought and process takes us closer to the final result.

The difference between art painting and software development is that software is continuously improving; while a painting once it’s done it’s done.

Let’s take CTEMP, our circulation temperature model as an example of how we improve its features to make it a benefit for our users.

CTEMP - Circulation Temperature

As the search for oil becomes more extreme, the wellbore circulating temperature prediction becomes very critical and in deepwater wells the complications can get more complicated by the presence of risers and choke/kill/boost lines. After combining ideas to create a software that deals with this matter, CTEMP was developed. Aside from predicting the wellbore circulating temperatures, this software addresses the transient heat transfer between the wellbore and the sea water/rock formation and it has interactive on-screen graphic results that provide guidelines for expensive HPHT drilling operations.

After all, with our creative activity and serious commitment we want our products to represent the inward significance of our artistic thinking.

Ingenuity Requires Persistence

There are several quotes from famous authors that talk about how “ingenuity can lead to significant rewards and how “persistence can be the key to survival. However, how high are the stakes when it comes to ingenuity and persistence in order to obtain significant rewards?

On the path towards any goal worth striving for, there are going to be obstacles, however, these obstacles cannot stop you from reaching your destination, it’s an opportunity to prove just how much this goal means to you. These are the moments in which to engage in persistence where you simply refuse to be deterred by the hurdles that one finds on any journey worth taking.

Increasing sophisticated and technological software is always the main goal; but simplicity and functionality are without a doubt very essential aspects of a software that must be kept in mind at all times during the developing process.

Technology is advancing unimaginably in today’s world. Each day new technology comes to live and brings the world better products. The drilling industry faces similar expectations and its growth isn’t just demanding but also fundamental for survival. With this in mind, we feel that our drilling software aims to achieve those goals fully. With the help of PVI software, companies worldwide can benefit not only by saving time, but also by saving money while making their operations more efficient and effective.

As an example of how ingenuity requires persistence let’s talk about HYDPRO, our drilling hydraulics model.

HYDPRO - Drilling-Hydraulics | Pegasus Vertex, Inc. - Drilling Software

When drilling a vertical or an extended-reach well, if the equivalent circulating density (ECD) is either too low or too high, it can cause serious problems or compromise the project. For this reason a successful drilling operation largely relies on achieving the optimal ECD, and an optimized drilling hydraulics software can allow engineers to plan ahead, improve drilling efficiencies and reduce the risks. HYDPRO is a well-developed model, but when it comes to its user-friendly design as well as the interfaces, users will find it very simple and operate it effectively. It provides 3D visualization for planning, as well as summaries and analysis results that can be generated in Word, Excel, and PowerPoint formats in no time.

HYDPRO covers all aspects of hydraulics, for instance:

  • Downhole circulating pressures
  • Surge and swab
  • Equivalent circulation densities (ECD)
  • Bit optimization
  • Hole cleaning
  • Cuttings concentration
  • Volumetric displacements

Thanks to a software like HYPDRO, the downhole drilling conditions can be cautiously examined and any potential problems can be identified prior to the job execution.

Today, our computer modeling is getting more advanced and the results are clearly worthwhile, because in the end is all about focusing on ingenuity and focusing on persistence.


The Art of Giving

This week we are going in a different direction toward our blog and we are taking this opportunity to talk about the art of giving. The art of giving is simply defined as giving from the heart without any expectation of something in return.

True giving and happiness are deeply connected and they both come from a place deep within our souls. A gift, no matter how small or large, is something that is enjoyed twice. First by the giver and then also enjoyed by the person who receives the gift.

The act of giving doesn’t have to be limited to holidays or special occasions. You can treat every person you meet as someone who you can give something special to. Let’s not think also that a gift is always something we purchase with our money. A very special form of giving can be personal acts of kindness. More so than we think, it’s not money or material things that people need, it's the things that can't be seen, like a good advice, a kind word, an appreciation, the sharing of some special knowledge, a compliment, a helping hand, some support during a difficult time or even a smile.

We all have something to give. We all have something of value for another person. With most things in this world, there is only a limited amount of what you can give away. Thankfully, generosity and kindness are not associated with these same material limitations and this makes the art of giving something wonderful.

One of life’s most basic laws is "every single act of love, kindness and generosity will multiply and return to you many times over". When you give without any desire of getting something back, your returns will be limitless. To give something from the heart is an action which will fill your life with joy.

The intention behind your giving is the most essential thing. The intention should always be to create happiness for both the giver and the receiver and when the intentions are the right ones it creates a pattern of happiness, joy, trust and love in your life beyond what you could ever expect.

Lao Tsu wrote a long time ago that "Kindness in words creates confidence. Kindness in thinking creates profoundness. Kindness in Giving Creates Love.” and that my friends is the art of giving.

Writers Blog, Readers Digest

“Though the sky is greyed with storm clouds deciding on if they should release their cargo on us or not, the sun is shining in my soul. Knowing that many times my words have been read makes the effort of creating something new every day all the more worthwhile.”
- John Thibeau (Canadian Writer)

Observing and reading are two of the most efficient ways of learning; they help us make sound and wise decisions when the situation calls for it.

As a writer, I have come to learn that the best way to express something and yet have an effect on the reader is by writing in a simple yet effective way where the foundation of the ideas, logic and purposes is well built. Even though we as writers express our own feelings with our writing, we do keep in mind what the readers want to read about and what interests them.

Writers write about what they observe in life, and that can lead them to have the desire to share all that information in just one article, but can the readers really benefit from all that vast information? Our intentions are the best, but the results are long articles that don’t have the effect intended. The readers will benefit more from articles that focus on a certain matter in which they can absorb the information and obtain good results from it.

In a similar way, we as software developers want our users to benefit from our software rather than getting lost in its complexity, trying to figure out how to use it. In our software development we focus on making the software easy to use, yet practical and professional.

Just like there’s a connection between writers and readers, there’s a big connection between developers and users. When ideas come to create or update a software, we think of ways to give our customers a simplified software, but at the same time a well advanced one, something they can really benefit from, sophisticated yet simple.

PVI Drilling Software - Sophisticated Yet Simple

Just like writers blog and readers digest, developers create and users benefit. At the beginning of the article we quoted from John Thibeau, who expressed how knowing that people were reading his articles was such an inspiration for him to write better articles, at PVI, we apply those words but with a minor change:

Knowing that many times our software is being used makes the effort of creating something new every day all the more worthwhile.

The Vision of Innovation

“Innovation is not the result of chance; it’s the result of action. It’s not a thing to wait for; it’s a thing to do.”
- Phil McKinney (Award winning author)

Innovation is defined as the act or process of introducing an idea, method or invention that creates value for its inventor as well as for the people that will benefit from its usage.

To be called an innovation, the idea must be reproduced at a competitive price cost and must satisfy a specific need. Innovation involves vision, application of knowledge; it includes all processes by which new ideas are generated and turned into useful products. In business, innovation results when the ideas are applied by a company in order to meet the needs and expectations of the clients.

In a social context the process of innovating is called:

The vision of innovation.

The vision of innovation is divided into two broad categories:

1. Evolutionary - Innovations that are constant and dynamically brought about by many incremental advances in technology or processes.

2. Revolutionary - Innovations that are sporadic and are often disruptive and new.

The vision of Innovation is synonymous with risk-taking; companies that create revolutionary products or technologies take on the greatest risk because they create new markets and they strive to be creative. So, what are we trying to say here? The companies that come up with breakthrough products and services are game-changers in their sectors or those that create new sectors relentlessly strive to follow a unique strategy. These companies are called “Visionary companies”, because they focus on achieving unique strategic aims, rather than innovation for innovation’s sake. This initiative results in breakthrough innovation.

As a drilling software company, we have a focused innovation initiative that is aligned with strategy. This is done through brainstorming, in compliance with the latest drilling technologies that generate ideas to come up with specific strategic methods, products and services. We use the vision of innovation as a tool that enables us to achieve our goals and that of our customers.

Innovative | Drilling Software - Pegasus Vertex, Inc.

One Hundred Percent

"I'll take fifty percent efficiency to get one hundred percent loyalty."
- Samuel Goldwyn (American Producer)

It’s well known that time and cost overruns are very common in the oil and gas industry. As a matter of fact, most projects deal with one or both problems, yet there is an alternative: the industry could reduce costs and accelerate projects by implementing advanced models that bring good benefits and are very efficient.

Being efficient means achieving maximum productivity with minimum wasted efforts and/or expenses.

For a company to have an effective way in its productivity there has to be a change that influences its efficiency; a change that identifies the difference between doing the right thing and doing things right.

In the beginning process of developing a software here at PVI, we put into consideration what is effective for our clients but more so, what is efficient. We think of what can be done to make our clients' workload lighter yet progressive. With our software, casing wear can be predicted, centralizer placement can be optimized, torque and drag can be calculated, mud reporting can be simpler, and many other things can be performed. One of our priorities is to produce a software that gives our clients their desired or intended result.

A software that’s efficient is a software capable of doing processes that save time, money and efforts. That's a good characteristic to have in a software, because it helps the companies that use it to be effective at getting results.

Efficient | Drilling Software - PegasusVertex, Inc.

Instead of just striving to design an effective software, we strive to design a software that is efficient at being effective. Similar to what Samuel Goldwyn stated, instead of taking 50% of efficiency, we intend to take 100% efficiency to get 100% of loyalty from our satisfied customers.