Tag Archives: cementing plug

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

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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.

Fig. 1—Pump-and-Pull Method

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 Two: Displacement

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After the cement slurries have been designed and formulated the next step is:

Cementing the Well

After the casing is run into the well, a cementing head is hooked to the top of the wellhead to receive the slurries from the pumps. Then there are two wiper plugs, also known as cementing plugs (bottom plug and top plug) that sweep the inside of the casing and prevent mixing the drilling fluids with the cement slurries. The bottom plug is introduced into the well, and cement slurries are pumped into the well behind it. The bottom plug is then caught right above the bottom of the well by the float collar, which functions as a one-way valve allowing the cement slurries to enter the well. The pressure on the cement being pumped into the well increases until a diaphragm is broken within the bottom plug, permitting the slurry to flow through it and up the outside of the casing string.

Once the proper volume of cement is pumped into the wellbore, the top plug is pumped into the casing pushing the remaining slurry through the bottom plug. After the top plug reaches the bottom plug, the pumps are turned off, and the cement is allowed to set. The amount of time it takes the cement to harden is called thickening time. For setting wells at deep depths, under high temperature or pressure, as well as in corrosive environments, special cements can be employed.

When it comes to cementing operations the ultimate and most difficult goal is to provide zonal isolation by displacing drilling mud with cement slurries because an incomplete mud removal causes a poor cement seal which can lead to a catastrophe.

PVI has developed CEMPRO+ with the capability of displacement efficiency for a successful cementing operation.

CEMPRO+ : Mud Displacement SoftwareThis software is designed for used for both land and offshore operations as well as conventional and/or foaming 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, complex wellbore geometry and many more.