How to choose a wellhead and tree model?

Operating an oil and gas well requires converting an artesian well to a well with a mechanical pumping configuration.

There are many things you need to consider during this process.

For example, a tubing hold-down device must be installed to ensure the correct pumping depth when extracting the downhole packer.

Removing the packer reduces the formation pressure and helps promote fluid flow.

In addition, the wellhead always needs to be rebuilt to meet certain pump requirements.

For example, you will find some pumping devices that remove the water blanket from the matrix section to improve the proper flow of the well.

 

Selecting a wellhead and tree model requires special consideration.

 

This article outlines some of the factors you should keep in mind when selecting a wellhead and tree model.

Wellhead and tree model selection

There are many factors to consider when determining the appropriate wellhead and tree model. These factors include:

 

Well conditions

 

Oil and gas wells are drilled deep underground.

Sometimes, drilling is done under a variety of different conditions that require special treatment.

For example, the pressure, temperature, and corrosiveness of the well can vary greatly.

In this case, you should choose the model of the wellhead and tree based on the behavior of the well.

Before choosing the wellhead and tree model, you should determine the temperature, pressure, and corrosiveness of the well.

Only after you understand how the well behaves, you can choose the temperature class, material class, pressure class, performance class, and product characteristics.

 

What do you want to achieve

 

Well, this should always be the first consideration.

The first thing you need to know is how you want to use the wellhead and tree model.

When choosing the wellhead and tree model, the purpose you want to achieve is very important.

In this way, you can view the model based on its purpose and scope of use.

 

 

Type of activity

 

When it comes to oil and gas production activities, we can judge it based on the location of the wellhead. Therefore, the type of production activities can be viewed in the following aspects:

 

Onshore oil production:

 

Wellhead and tree models must meet the requirements of onshore oil exploration, drilling, and production.

Onshore gas production: Similar to onshore oil production, there are certain specifications to consider for discovering and producing natural gas.

Before deciding on the wellhead and Christmas tree model, consider the pressure and temperature requirements for onshore gas production.

 

Offshore Wellhead:

 

First, the wellhead is a structure placed on the seabed where the well is drilled.

 

The wellhead can be a single unit or a block of multiple units, where the subsea Christmas tree is placed on top of the wellhead as a control unit.

Offshore wellheads are located on the production platform, also known as surface wellheads.

 

Choosing a wellhead and Christmas tree model may depend on the location of the wellhead.

 

For example, is it an offshore wellhead or a subsea wellhead? You need to know which model is more suitable for offshore operations and which model is more suitable for onshore operations.

 

The size of each wellhead and Christmas tree equipment

 

The size of the various components of the wellhead device and Christmas tree determines the model used. For example, surface casing, hanging casing, hanging tubing, etc., can help you identify the model of the wellhead device and Christmas tree.

 

From the component perspective, each wellhead device and Christmas tree equipment should be identified and considered separately;

 

Let's take a look.

 

1. Bare rod

 

A bar that is too short may cause problems, especially when operating in difficult wells.

Also, workers may drop the rod string to tap the bottom or complete other maintenance tasks.

A properly sized polished rod allows it to drop completely to the highest point of the stuffing box without causing trouble.

 

2. Bare Rod Clamp

 

When delivering oil and gas, bare rod clamps are used to reinforce the rod string, while the additional weight rests on the carrier rod and sling.

In some cases, two bare rod clamps may be required for added safety.

The purpose of adding this safety device is to assist the rod string and prevent it from entering the stuffing box. Bare rod clamps prevent various spills.

 

3. Check Valve

 

It is well known that check valves are a problem for wellheads.

Scale or trash accumulated under the check valve seat or internal failures may cause the check valve to not provide a proper seal.

In addition, these problems may cause oil or gas to escape and flow back into the wellbore.

Therefore, it is necessary to consider this equipment and maintain it properly to ensure efficient operation.

 

Selecting the model of wellhead equipment and oil production tree may not be as simple as you think.

Likewise, it should not be an overly daunting task.

Once you know what to look out for, the whole process becomes simple and straightforward.