Casing and cementing involves running and cementing steel pipe (casing) into drilled wellbore sections to prevent collapse and seal off formations. Casing comes in various diameters, lengths, and strengths. It is run and connected using tools like elevators, spiders, and tongs. A typical cementing system uses centralizers, scrapers, and plugs to pump cement down the casing and up the wellbore annulus to isolate formations and seal the well. The cement job is monitored and considered complete when the calculated amount of cement has been displaced and the top plug separates from the bottom plug.

1. OPERATIONS GEOLOGY
PRESENTATIONS
Presentation 7:
Casing & Cementing
25 November 2016Ali Trichelli

2. LEGEND
 Casing & Cementing
 Overview
 Casing Accessories & Casing Running Tools
 Typical Cementing System ( for a land well)
 The Cementing Job (of a Casing String)

3. Overview
 Every well is drilled in sections and each section has to be cased and cemented (see well profile)
 Casing is a steel pipe that has to be set in the borehole to prevent it from caving in and to seal
off formations
 Casing has to be cemented and held in place
 Casing comes in different lengths (4.88m to 14.63m) and Diameters (5in to 30in). Casing also
comes in differents grades or strengths depending on the well’s characteristics
 The main casing types are:
 Conductor casing to prevent cave-ins of near surface formations
 Surface casing to avoid contamination of the fresh water zone of near surface formations
 Intermediate casing to seal off troublesome zones to prevent problems when drilling the
deeper formations. Deep wells may require more than one intermediate casing
 Production casing or liner to protect and isolate the producing zone

4. Casing Accessories & Casing Running Tools
 Casing Running Tools include Heavy duty elevators, casing spiders and power
casing tongs. These tongs are used to screw the threaded connections of the
casing joints together and torque them to the correct amount.
 Liner hanger is used in case the production casing is not run all the way to
surface
Casing Accessories
Casing Running Tools
Casing Spider Casing Elevator Power Casing Tongs

5. Typical Cementing System for a Land Well
The one way valve
in the float collar
lets the casing
string float into the
well to lessen the
load on the hoisting
system

6. The Cementing Job of a Casing String
The guide shoe guides the
casing joints into the
borehole and is open to let
the drilling mud go through
The one way valve in the
float collar lets the casing
string float into the well to
lessen the load on the
hoisting system
Centralizers to keep the
casing off the wall of the
hole to ensure good cement
job
Scratchers to remove wall
cake to ensure good cement
bond to the wall of the hole
The bottom plug wipes
mud off the inside of the
casing & separates the
mud from the cement
The top plug follows the last of
the cement into the casing &
wipes cement off the inside of
the casing & separates cement
from the displacement fluid
When the calculated amount of
cement has been pumped, the
top plug is released and pushed
by the displacement fluid until it
sits on the bottom plug (a sharp
increase of the cement pump
pressure will be observed). The
cement job is hence complete.

7. Next Presentation
 Cutting Sample Examination
 Introduction
 Source of the Cutting Samples
 Lag Time Determination
 Cutting Preparation & Sample Types
 Handling of the Drill Cutting Samples
 Sample Contamination
 Cuttings Sample Description
 Rock Type
 Classification
 Color
 Hardness/ Induration
 Grain Size/ Grain Shape
 Sorting
 Luster
 Cementation/ Matrix
 Visual Porosity
 Accessories/ Inclusions
 Hydrocarbon Show Evaluation- Oil
 Hydrocarbon Show Evaluation- Gas
 Shipment of the Cutting Samples