Oilfield cementing is the procedure of developing and pumping cement into a wellbore. Cementing helps to protect and seal a wellbore. Cementing provides zonal isolation and assists in safeguarding and closing a wellbore.
It is a part of preparing a well for production and a drilling process. This exclusive process is utilized to cut off water penetration into the well permanently.
Oilfield Cementing Process:
The oilfield cementing process starts with adding cement slurry into a wellbore by using cementing pumping. The drilling fluids used within the well are replaced for the drilling production process.
The newly added cement slurry flows to the bottom of the wellbore through the casing which eventually becomes the pipe through which hydrocarbons flow to the surface. The cement fills in the space between the casing and the wellbore and hardens.
The thickening time is analyzed by the operators. The set cement becomes a newly created seal that prevents external materials from entering the well’s flow. The seal also helps permanently position the casing into place.
Purpose of Oilfield Cementing Process:
Oilfield cementing is used to abandon a lost circulation zone or an area where there is a chance of reduction or absence of flow in the wellbore.
The cementing process is performed when the cement slurry is deployed into the well through the pump while displacing the drilling fluids placed within the well and substating them with cement.
The cement slurry flows into the bottom side of the wellbore through the casing. It will flow gradually to the pipe through which hydrocarbons flow to the surface. It fills in the holes and spaces between the casing and the wellbore and hardens.
This process will ensure a seal so that the outside materials cannot enter into smooth flow and it will position the casing in place. Cementing services are essential for the successful completion of any oilfield project. It is important to ensure that the cementing process is done correctly and efficiently to ensure the safety of the wellbore and the surrounding environment.
What is Zonal Isolation?
Zonal isolation is an essential part of oilfield cementing which is not directly associated with the production but still is a significant task. Zonal isolation prevents the fluids such as water or gas in one zone from mixing with oil in another zone.
This is done through the creation of a hydraulic barrier between the casing, cement, and formation. Zonal isolation seeks to segregate undesirable intervals from production. This is accomplished during the well’s construction phase when casings and liners are cemented in place.
Types of Oilfield Cementing:
Cementing options can be divided into two broad categories i.e primary cementing and remedial cementing.
Primary Cementing: The objective of primary cementing is to provide zonal isolation. Cementing is the procedure of mixing a slurry of cement, cement additives, and water and pumping it down through the casing to critical points, in the annulus around the casing. The two principal functions of this cementing process are:
- To restrict the fluid movement between the formations
- To bond and support the casing
- Remedial Cementing:
Remedial cementing is usually performed to correct problems associated with the primary cementing operation. The most economical and successful approach to remedial cementing is to avoid it by thoroughly planning, designing, and executing all drilling and completion operations. Remedial cementing operations consist of two broad categories:
· Squeeze cementing
· Plug cementing
Cement Placement Procedures:
In general, there are five steps required to obtain successful cement placement and meet the objectives previously outlined.
- Analyze the well’s parameters; define the needs of the well, and then design placement techniques and fluids to meet the needs for the life of the well. Fluid properties, fluid mechanics, and chemistry influence the design used for a well.
- Calculate fluid (slurry) composition and perform laboratory tests on the fluids designed in Step 1 to see that they meet the needs.
- Use necessary hardware to implement the design in Step 1; calculate the volume of fluids (slurry) to be pumped; and blend, mix, and pump fluids into the annulus.
- Monitor the treatment on time; compare with Step 1 and make changes as necessary.
- Evaluate the results; compare with the design in Step 1 and make changes as necessary for future jobs.
Parameters of Well for Oilfield Cementing:
To keep the zones isolated, it is critical to consider the wellbore and its properties when you are designing a cement job.
- Depth: The depth of the well affects the cement slurry design because it influences the following factors: Amount of wellbore fluids involved Volume of wellbore fluids Friction pressures Hydrostatic pressures Temperature
Wellbore depth also controls the hole size and casing size. Extremely deep wells have their distinct design challenges because of:
- High temperatures
- High pressures
- Corrosive fluids
- Wellbore geometry:
The geometry of the wellbore is important in determining the amount of cement required for the cementing operation. Hole dimensions can be measured using a variety of methods, including:
- Acoustic calipers
- Electric-log calipers
- Fluid calipers
Open hole geometry can indicate adverse conditions such as washouts. Wellbore geometry and casing dimensions determine the annular volume and the amount of fluid necessary.
- Temperature :
The temperatures of the wellbore are critical in the design of a cement job. There are three different temperatures to consider:
- bottom hole circulating temperature (BHCT)
- bottom hole static temperature (BHST)
- Temperature differential (temperature difference between the top and bottom of cement placement)
The use of cement is ideal for the firm structure of the buildings. All the oilfields need solid structures for their buildups to store their oil products.
Therefore, it is essential to construct the driveways and other passage areas for easy and quick movements of trucks and other heavy machinery.
Prismecs provides a complete service of cement grinding and storage solutions. Industries prefer to hire reliable services for oilfield cementing.
Our expert engineers use waterproof material, cutting-edge technology, and efficient construction strategies to provide a solid and attractive construction. It is ideal for making their projects durable and safe from weather hazards.
Metadescription:
Oil field cementing seems to be a demanding job. Prismecs provide oilfield and well cementing services with customized solutions that perform consistently in every situation. Visit www.prismecs.com to avail of our services.
