Pre-running procedures Always pre-plan Ensure proper layout on the rig rack Joints need to be laid out properly especially when dealing with different weights of casing in one run. Clean the threads. Once the thread protectors are removed the threads should be cleaned. The tubular interiors should be inspected. Handling procedures Use thread protectors Use … Continue reading Running Casing
Tag: Drilling Engineering
Wellbore Tubulars
Casing hanger – this is installed to support the individual casing strings in the well. This is the landing base or casing head. This is usually welded or screwed to the top of the surface casing string. The surface casing string serves as a foundation pile for the well. This transfers the hanging load to … Continue reading Wellbore Tubulars
Mud Motor Operations
Motor check prior to operation. Drill bit jet size check Operation of the bypass valve While tripping into the hole, circulation should be broken every 20 to 30 stands to keep the motor running freely. At total depth and before drilling circulation is begun and set to close the bypass valve and start the motor … Continue reading Mud Motor Operations
A Guide to Bit Running Procedure
Rig Site Protocol PPE Sign In Reverse Park Vehicle Present yourself to Company personnel State purpose of visit Explain objectives and plan Rig and Surface Equipment Evaluation Solids Control Equipment Ineffective or too few shakers can limit the speed at which cuttings can be removed from the mud system. This may result in lowered penetration … Continue reading A Guide to Bit Running Procedure
A Guide to Reaming
Always Plan your tripping schedule: Record tight spots from previous trips Know the wellbore geometry; the deviation, doglegs etc. maintain constant communication with your directional personnel. Despite pulling up always be prepared to run downward. This may be needed to free the pipe after a connection. One example is the consistent execution of 200 to … Continue reading A Guide to Reaming
A Guide to Hole Cleaning
Hole cleaning is an essential part of drilling. It ensures that the material that is drilled is effectively and efficiently being removed from the wellbore. Failure to achieve proper hole cleaning can result in a host of wellbore problems and issues. Indications of poor hole cleaning: Excessive pull on trips High rotary torque Lowered rate … Continue reading A Guide to Hole Cleaning
Perforations
This is done to provide affective flow communication between reservoir and wellbore. The perforating jobs is irreversible and as such requires good planning. The shaped jet perforator is mechanically simple and reliable, with generally higher performance. Suits a wider range of completion needs. The wireline methods have offered depth control, selective firing speed and low … Continue reading Perforations
Effect of bit on Rotary Assembly
Roller Cone – makes very little difference on the build, hold or drop angle. This type of bit does influence the walk rate. They have a right walk tendency, long tooth bits exhibit this more than short tooth bits. PDC – no walk occurs. They do affect the inclination. The gauge length of the … Continue reading Effect of bit on Rotary Assembly
Control with a Rotary Assembly
Side Force and Tilt Essentially these are the forces and angles that determine and influence where the bit goes. Bit Trajectory Stabilizer gauge and placement Drill Collar length and diameter Weight on bit Rotary Speed Bit type Formation Flow rate Rate of penetration Build Assemblies To increase the build rate – longer distance between near … Continue reading Control with a Rotary Assembly
Cementing Additives and Mechanisms
There are 8 general categories of additives. Accelerators – Reduces setting time and increases the rate of compressive strength build up. Retarders – Extends the Setting time. Extenders – Lowers the density. Weighting Agents – Increases density. Dispersants – Reduces viscosity. Fluid Loss Control Agents. Lost Circulation Control Agents. Specialty Agents. Accelerators Can be … Continue reading Cementing Additives and Mechanisms
Why Cement (a wellbore)?
The reasons are as follows; To support the vertical and radial loads applied to the casing Isolate porous formations from the producing zone formations Exclude unwanted sub-surface fluids from the producing interval Protect casing from corrosion Resist chemical deterioration of cement Confine abnormal pore pressure Cement is introduced into the well by means of a … Continue reading Why Cement (a wellbore)?
Replaceable Sleeve Stabilizer
Liner Completion
Stabilizer-Integral Bladed
Conventional Completions
Casing Flow; means that the producing fluid flow has only one path to the surface through the casing. Casing and tubing Flow; means that the there is tubing within the casing that allows fluid to reach the surface. This tubing can be used as a kill string for chemical injection. The tubing may have … Continue reading Conventional Completions
Chemical Treatment of Drilling Fluids
Chemical treating agents reduce flocculation in clay water drilling fluids by one of more of the following mechanisms; Removal of contamination be precipitation Reducing the contaminant effect by sequestering the contaminant Neutralizing flocculation by satisfying cationic charges on the clay particles Forms a protective film around the clay particles Phosphates Powerful anionic dispersants, only … Continue reading Chemical Treatment of Drilling Fluids
Types of Clays
The first type is needle spaded non-swelling clays eg. Attapulgite or sepiolite. The shape of the clay allows it to build viscosity. As a result of their shape and poor swelling characteristics they don’t exhibit poor filtration control. Attapulgite is used primarily as a viscosity builder in saltwater fluids. Sepiolite is used as a supplemental … Continue reading Types of Clays
Drilling Fluids: Suspend and Release Cuttings
The mud must trap the cuttings while drilling but at the same time it must allow the solids control equipment to be able to remove the drilled solids. If cuttings settle out during the drilling process then this may bridge the well bore and cause problems. Also if the fluid is not designed properly then … Continue reading Drilling Fluids: Suspend and Release Cuttings
Drilling Fluids: Cuttings Removal
As the cuttings are drilled they must be removed and brought to the surface through the annulus. The removal of the cuttings is a function of the size, shape and density in combination with the rate of penetration (ROP), drill string rotation, viscosity, density and annular velocity of the drilling fluid. Viscosity - higher viscosities … Continue reading Drilling Fluids: Cuttings Removal
(Oil)Well Bore Packers
Packer Applications Casing Protection Separation of multiple Zones Isolation Packers Elimination of Surging and heading Sub-surface safety control Artificial/Gas LiftThere are three types of packers; mechanical and hydraulic set and permanent. All packers fall into one or a combination of these.Mechanical Set Packers- These are set by some form of tubing movement, usually a rotation … Continue reading (Oil)Well Bore Packers