Behind the Scenes: What Professional Expertise Powers Pump-and-Pull Cementing Success?

Posted on April 9, 2024 by PVI

In the realm of oil and gas extraction, setting a cement plug to seal off fluid movement in wells is a critical task. Whether it is for well abandonment or providing a starting point for sidetrack drilling, achieving a reliable seal demands precision and expertise.

While the classic gravity-assisted balanced plug technique holds its own in vertical or moderately deviated wells, we're talking about a whole new ball game when it comes to horizontal or highly deviated holes. In those situations, it's time to pivot and explore alternative strategies. The industry successfully practiced the pump-and-pull method (Fig. 1). Unlike its gravity-dependent counterpart, pump-and-pull does not rely on gravity alone to spot the cement plug. Instead, the cementing crew pulls the pipe out of the hole while simultaneously pumping fluids into it. This approach offers superior control during plug placement, minimizing the risk of cement stringing out—an invaluable advantage in highly deviated or horizontal wells.

Let's face it, executing pump-and-pull jobs comes with its fair share of challenges. Synchronizing pulling speed with pumping rate is paramount to minimize contamination, making meticulous flow rate design critical. During the design phase, predicting fluid tops and slurry contaminations, along with calculating pumping pressure and downhole equivalent circulating density (ECD), are essential—but manually crunching these numbers in the face of complex wellbore structures, survey data, and pump sequences proves inefficient.

Enter PlugPRO – Cement Plug Placement software, a successful computer model in cementing design. PlugPRO introduces an innovative "pump-and-pull" feature alongside its existing balanced plug and dual annulus methods (Fig. 2), empowering engineers to tackle complex plug jobs with confidence.

Fig. 2—Existing Balanced Plug and Dual Annulus Methods in PlugPRO

This feature offers three distinct options for pump-and-pull simulation, catering to various operational scenarios:

1. Sacrificial Cement: This method involves initially pumping a controlled amount of cement into the annulus before initiating the pump-and-pull operation (Fig. 3). The synchronization of pulling speed and pumping rate is crucial to effectively mitigate contamination risks in this method.

Fig. 3—First Pump-and-Pull Method: Sacrificial Cement

2. Pump and Pull after Cement Placement: Tailored for open holes, this method allows for the displacement of a significant portion of the cement slurry to the desired plug top, with the stinger positioned at the bottom depth of the cement (Fig. 4).

Fig. 4—Second Pump-and-Pull Method: Pump and Pull After Cement Placement

3. User-Defined Pump-and-Pull: Providing unmatched flexibility, this option empowers engineers to customize pump-and-pull sequences according to specific operational requirements (Fig. 5). By doing so, engineers can gain a comprehensive understanding of progress and identify any potential synchronization issues proactively.

Fig. 5—Third Pump-and-Pull Method: User-Defined Pump-and-Pull

PlugPRO now stands out as the go-to solution for enhancing pump-and-pull cementing operations. By precisely computing essential results such as fluid tops, pump pressure, ECD, temperature, and more, it empowers engineers with the tools they need to carry out their tasks with precision and confidence. With PlugPRO at their disposal, professionals can rely on the dependability and effectiveness of their cementing jobs, guaranteeing favorable results in the field.

Ready to take your plug jobs in cementing to the next level? Watch the video below to learn the Pump-and-Pull methods mentioned in this article and start mastering your technique.

For more information on the features of PlugPRO, visit our website:

www.pvisoftware.com/plugpro-cement-plug-placement.html

Explore PlugPRO firsthand - contact us at info@pvisoftware.com to schedule a complimentary demo.

Let’s elevate your cementing operations together!

Step One: Preparation

Posted on March 10, 2015 by Freddie Ruiz, PVI

Cementing a well is the procedure of developing and pumping cement into a wellbore. Although it is used for various reasons, cementing protects and seals the well. Very frequently, cementing is used to permanently block out water from penetrating the well. Cementing is also used to seal the annulus after the casing string has been run in the wellbore. In addition, cementing can be used to seal a lost circulation zone, or a specific area where there is a reduction or absence of flow inside the wellbore. When it comes to directional drilling, cementing is used to plug an existing well, in order to run a directional well from that point.

Cementing is performed when the cement slurries are placed into the well by pumps, displacing the drilling fluids that are still located in the well, and replacing them with the cement. The cement slurries flow to the bottom of the well through the casing, which will later be the pipe through which the hydrocarbons flow to the surface. From there it starts filling the space between the casing and the wellbore, and hardens. This permanently positions the casing in place and seals the wellbore so that outside materials cannot enter.

Preparing the Cement

When preparing a well for cementing, it’s very important to be certain of the amount of cement required for the job. This is done by measuring the diameter of the borehole along its depth. Also, to know the required properties of the cement is very essential before beginning any cementing operation. The proper set cement is good to be determined, including the density and viscosity of the material, before actually pumping the cement into the hole.

Special mixers are used to combine dry cement with water to create the wet cement that is also known as slurry. The cement used in the well cementing process is Portland cement, and it is calibrated with additives to form one of eight different API classes of cement. Each is employed for various situations.

Additives can include accelerators, which shorten the setting time required for the cement, as well as retarders, which do the opposite and make the cement setting time longer. In order to decrease or increase the density of the cement, lightweight and heavyweight additives are added. Additives can be added to transform the compressive strength of the cement, as well as flow properties and dehydration rates. Extenders can be used to expand the cement in an effort to reduce the cost of cementing, and antifoam additives can be added to prevent foaming inside the well. In order to plug lost circulation zones, bridging materials are also added. However, the critical part missing here is the management of numerous reports and search function.

Without an efficient lab database, we will face the following situations:

Difficulty of designing cement slurries.
Waste of resources to repeat similar tests.
Lack of prove while job problems occur.
Non-standard practices at various labs within a company.

To streamline the cement lab operation, PVI developed CEMLab:This software is an integrated database management application that:

Formulates slurries.
Calculates lab amounts for all ingredients, such as cement, dry and liquid additives, salts and water.
Generates weigh-up sheets.
Stores API test results.
Generates lab reports.

CEMLab, is a web based application that allows quick access to all of your slurry formulations and testing statuses from anywhere, at any time. The advanced search function allows users to find the formula and test quickly and brings the previous jobs to their screen in no time. It’s a great tool for preparation.

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.

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.

5 Benefits of Drilling Software Training

Posted on May 13, 2014 by Gefei Liu, PVI

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.

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