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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!

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.

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

Hot Game with Hot Model