Oil Well cementing , Main components of cementing. pptx

Main components of well cementing;.
Cement head - A device fitted to the top joint of a casing string to hold a cement plug before it is pumped down the casing during the cementing operation.
Float collar - A component installed near the bottom of the casing string on which cement plugs land during the primary cementing operation. It typically consists of a short length of casing fitted with a check valve.
This device may be a flapper-valve type, a spring-loaded ball valve or other type.
Guide shoe - A tapered, often bullet-nosed piece of equipment often found on the bottom of a casing string.
The device guides the casing toward the center of the hole and minimizes problems associated with hitting rock ledges or washouts in the wellbore as the casing is lowered into the well

1. Oil Well Cementing

2. Cement head - A device fitted to the top joint of a casing string to hold a cement plug before it is pumped down the casing during the cementing operation. Float collar - A component installed near the bottom of the casing string on which cement plugs land during the primary cementing operation. It typically consists of a short length of casing fitted with a check valve. This device may be a flapper- valve type, a spring- loaded ball valve or other type. Guide shoe - A tapered, often bullet-nosed piece of equipment often found on the bottom of a casing string. The device guides the casing toward the center of the hole and minimizes problems associated with hitting rock ledges or washouts in the wellbore as the casing is lowered into the well.

3. Cement plug -A rubber plug used to separate the cement slurry from other fluids, reducing contamination and maintaining predictable slurry performance. Two types of cementing plug are typically used on a cementing operation. The bottom plug is launched ahead of the cement slurry to minimize contamination by fluids inside the casing prior to cementing. A diaphragm in the plug body ruptures to allow the cement slurry to pass through after the plug reaches the landing collar. The top plug has a solid body that provides positive indication of contact with the landing collar and bottom plug through an increase in pump pressure.

4. Well Cleaners These are used to assist in clearing the mud cake when running the pipe by reciprocation or rotation. There are two types: Scratchers Well- bore Wipers

5. This is more critical in deviated wells than in straight holes. We must not use too many as we will be unable to get the casing into the ground. Frictional forces will be greater than the pipe weight. EFFECTIVE CENTRALIZER

6. After casing, or steel pipe, is run into the well, an L-shaped cementing head is fixed to the top of the wellhead to receive the slurry from the pumps. Two wiper plugs, or cementing plugs, that sweep the inside of the casing and prevent mixing: the bottom plug and the top plug. Keeping the drilling fluids from mixing with the cement slurry, the bottom plug is introduced into the well, and cement slurry is pumped into the well behind it. The bottom plug is then caught just above the bottom of the wellbore by the float collar, which functions as a one- way valve allowing the cement slurry to enter the well. Then the pressure on the cement being pumped into the well is increased until a diaphragm is broken within the bottom plug, permitting the slurry to flow through it and up the outside of the casing string.

7. After the proper volume of cement is pumped into the well, a top plug is pumped into the casing pushing the remaining slurry through the bottom plug. Once 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 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.

8. Cementing cementing is the process of mixing a slurry made up of cement/additives and water. Cementing is one of the most critical steps in the drilling and completion of oil or gas wells Cement plugs may also set in the wellbore to isolate zones e.g. loss zones, high pressure zones, water bearing zones Well cementing technology is the application of many scientific and engineering disciplines

9. Primary Cementing Process of placing cement in the annulus between the casing and the wellbore Objectives: Provide Hydraulic Seal Create Zonal Isolation Protect Useable Water Provide Structural Support for Casing Protect Casing from Corrosion Isolate Casing Seat for Subsequent Drilling

10. Primary Cementing Starts with a Plan The plan should take well from drilling through plugging The well plan includes: Wellbore Environment Well Type Casing and Cement Program Mud System Type of Completion

11. Effective Primary Cementing Good drilling practices and mud properties Casing movement while cementing Centralization of the casing Optimal borehole pipe clearance Use of spacers and mud flushes

12. Fundamentals of Cement Placement Casing Hardware Float Equipment Centralizers Wiper Plugs Multi- stage tools Hole conditioning and mud properties Mud Rheology Gel Strength Fluid Loss Circulation Rate Filter cake removal Casing movement while cementing Rotation Reciprocation Use of spacers and mud flushes

13. Variables Affecting Zonal Isolation BOREHOLE: Size, shape, uniformity BOREHOLE STABILITY: Lost circulation, flows, structural integrity and characteristics of formations CEMENTING PROCESS: Displacement design, job execution, cement volumes, cement material properties MATERIAL PROPERTIES: Cement, relationships between pipe-cement-formation PRESSURE AND TEMPERATURE CHANGES/CYCLING Over the life of the well GEOMECHANICS: In-situ stresses, change in stresses along borehole, change in stresses in cement and pipe GEOLOGY/GEOCHEMISTRY: Formation type, structure, formation fluid chemistry CHEMISTRY: Corrosion and chemical resistance of casing and cement

14. 3- D Computer Modeling of Displacement of Mud by Spacer and Cement Courtesy of Benefits of Pipe Rotation During Cementing No Pipe Rotation 20 RPM Pipe Rotation

15. 100% Excess Shallow Shales 17 1/2' Cmt to Surf. Vertical < 2º 13 3/8", J- 55 13 3/8" Shoe 1,500' 1,500' 54.5# CIT 300 PSI / 30 min 12 1/4" 11.0 PPG FIT Base/Heebner Shale (GDS) 6,861' 9 5/8" TOC 7,500' 7,500' TOC ~1,000' Vertical above Deese Deese (GDS) 8,789' 5 1/2" TOC 10,800' 10,800' Primrose (Morrow ) 11,459' Springer Shale 11,838' 9 5/8", L-80 9 5/8" Shoe 11,900' 11,900' 40# CIT 1500 PSI / 30 min 12.5 PPG FIT Swell packer @ 7,000' TOC 1,000 into Build: 14-16º/100 Black Marker 13,174' 8 3/4" 9 5/8" Csg Springer 2 (false caney) 13,743' Springer 3 (false caney) 14,059' 23#, P- 110, Blue KOP 14,400' 14,400' Caney 14,414' Woodf ord EOB 14,731' 14,901' 15,310' LOL: 4,950 TD: 20,260 TD TVD: 14,721 Current Well Design – Deep Intermediate Casing FORM. / CSG TVD MD CASING PROFILE HOLE SIZE CSG SPECS MUD INFO NOTES 50' 50' 20"

16. Newfield Mid- Continent Operations Drilling Mud circulated until it has the required properties Casing is Centralized Casing is reciprocated rotated during cementing On the production casing a swell packer is run and set inside intermediate casing string Using TergoVis! Efficiency Fluid

17. Newfield Mid- Continent Operations Completions Test annulus between the production casing and intermediate casing for pressure Annular pressure monitored during hydraulic fracture treatment Production casing pressure tested to 80% of yield before pumping hydraulic fracture treatment Production casing attached to automatic shut downs and relief lines while pumping job

18. Zonal isolation for each well must be designed and constructed with regard to its unique geological environment. There is no single fit- for- purpose design, well construction, or barrier verification process that is right for all wells. The barrier system that protects usable water includes surface casing and cement. Verification of the barriers is typically accomplished by both pressure testing (direct measurements of casing and shoe cement) and by an operational evaluation (cement placement behind pipe). There is no direct measurement available to verify a cement barrier behind casing at this time. Summary