Cementing tools

Cementing tools accessories

What is Cementing Tools? This is an article about the Cementing tools accessories basics.It includes all basic info about cementing tool.It is wrote by myself,Maybe there is mistake,It is my pleasure that you point it to me.

　　The cementing wellhead tool accessories refers to a mechanical device that is mounted on the casing for the purpose of solidifying the well during the cementing process.Here, I introduce it in 2 items:

　　Wellhead Cementing Tools Introduction and Downhole Cementing tool introduction

Part 1—Cementing wellhead tools

Cementing wellhead tool includes:

1–Cementing cement head

• Casing cement head (single plug cement head, double plug cement head)
• Liner pipe cement head (Kelly Pipe cement head, tubing cement head)
• Cementing plug (top rubber plug, bottom rubber plug, liner pipe rubber plug).

2–Circulating joint (water hose interface, square drill sweat interface)

3–Water hose connection sub

4–Cementing Manifold

5–High pressure valve

Cement Head

Definition: It is connected between the upper end of the casing string (or tail pipe column) and the cementing pipe sink. The inside can accommodate the solid rubber plug, which is used to complete the wellhead device for cementing operation.

CEMENTING HEAD FUNCTION:

Complete the construction process such as circulation, injection isolation liquid, grouting cement, release rubber plug and slurry, etc. It is the general hub of the consolidation and grounding pipe wellhead. To withstand high pressure, adapt to a variety of process cementing. When the floating hoop floating shoes fail, the rolling can be achieved and the cement slurry can be prevented from flowing backwards.

Types:

As per installation string, : casing cement head and liner pipe cement head.

As per plug quantity:single plug cement head and double plug cement head.

CEMENTING HEAD STRUCTURE：

Mainly consists of body, end cover, stop pin, Union, manifold, quick connector, etc.

Cement Plug

Definition: It is a rubber product used to isolate different liquids in a cementing operation.

FUNCTION:

• Separate different liquids and scrape the drilling fluid or cement slurry on the inner wall of the casing.
• When the collision is completed, a pressure signal is given to indicate that the consolidation operation is completed.
• It ensures the length of the cement plug in the casing and the quality of the cement ring of the casing shoe attachment.

Types:

As per cementing plug usage, it can be divided into cementing plug on the casing, cementing plug under the cementing plug, self-locking cementing plug, cementing plug at the tail pipe, cementing plug for classification and cementing plug, anti-rotation cementing plug

CEMENTING PLUG STRUCTURE

Cementing plug structure: it consists of a core, a rubber bowl and a ply. The rubber plug core is made of pig iron, cast aluminum, glass steel or hard rubber, etc., which is made of rubber, and then vulcanized into the inner core body to form a rubber plug. Most of them are now made of aluminum.

Circulating Sub

Definition: The tool used to connect the wellhead casing string to the ground circulation system to achieve circulation is called a casing circulation sub.　

Function:

The Kelly Pipe-casing circulation joint is used when the drilling fluid needs to be circulated in the middle of the casing, and the casing can be moved up and down when the casing is blocked.The hose with a casing circulation joint is used when circulating the drilling fluid after the casing is completed, and can also be used for surface cementing operations.　　

Types：

According to the use can be divided into: square Kelly drill pipe – casing circulation sub, water hose with a casing circulation joint (also called casing circulation hat), drill pipe circulation sub.　　

Structure:

the Kelly pipe -casing circulation sub is a male thread with a sleeve at one end and a female thread of the drill rod at the other end;　　

The water tap has a circulation joint, which is a male thread with a sleeve at one end and a two-way joint with a short joint at the other end.

Hose joints

Definition: The joint used to connect the hose and the wellhead cementing tool (cement head or belt casing loop joint).

Function:

It is used to connect the pulping process during cementing and cementing; now, when circulating well washing, the casing is circulated.

It is used to connect the water hose and the casing cement head to complete the hose for connecting the gongs and the hoses installed at the wellhead.

Classification:　　

According to the specifications can be divided into: 4 ” x 2″ and 5 ” x 2″.

According to the conversion joint type can be divided into two male joints, female x male joints.

Structure:

The hose joints are mainly composed of different sizes of high pressure joints connected by union, including union head,union ring, sealing ring.

Cement Manifold

Definition: It is device that mainly composed of high pressure valve, high pressure union, high pressure tee and high pressure Manifold. It is used to connect cementing equipment and cementing wellhead tools.

high pressure valve, high pressure elbow

Main Application: It is used to switch hydraulic passages and connect cementing Manifolds.

Part 2—Downhole Cementing tools

Downhole Cementing Tools include

　　1.Float Collar, Float shoe,Guide Shoe.

　　2.Casing centralizer (rigid, plastic)

　　3.Stage Cementing Tool (mechanical, hydraulic, drill-free)

　　4.Internal pipe method cementing device (well base type, wellhead seat type).

　　5.Liner Hanger,(mental, hydraulic, double-acting

　　6.Outer casing packer (hydraulic expansion, self-expanding)

　　7.Other casing accessories (Stop Collar,location ring, cement umbrella, scraper, etc.)

Casing float Collar,Float Shoe

Definition: Installed in the bottom part of the casing string, with a back pressure device. When the casing is under the cover, the short section of the casing that can generate buoyancy is called a float collar.The casing guide shoe that can generate buoyancy is called a float shoe.

Function:

• Prevent the drilling fluid in the wellbore from entering the casing during the casing process to reduce the weight of the casing.
• Elimination of the drilling fluid outside the pipe, allowing it to return in the wellbore, is conducive to cleaning the well wall.
• After cementing, the cement slurry can be prevented from flowing back into the casing.
• The inner baffle of the casing float collar can support the rubber plug, and the casing floating shoe can guide the casing to smoothly enter the well.

Classification:

• The drilling fluid entering mode when pressing the well can be divided into self-filling type and non-self-filling type;
• According to the working mode of the back pressure device, it can be divided into floating ball type, spring type and tongue type

Float Collar

Structure: The float collar is mainly composed of two parts: the main body and the valve core (back pressure device).

Float shoe

It is also includes guide shoe.The floating shoe is a combination of a guiding shoes and a floating collar, which has both the function of guiding the shoe and the function of the floating collar.Different types of floating collar and floating shoes have the same structure.

Stage Cementing Tool

Definition: A special device installed at a predetermined position on a casing string for continuous or discontinuous cementing operations in two or multi stages.

Usage principle:

• the formation can not withstand the pressure formed by the long-term cement slurry.
• There is a long length between the two target layers that does not require cement sealing.
• It is difficult to meet the requirements of construction design for one time.

Classification:

According to the action form, it can be divided into mechanical type (plastic plug type) and hydraulic type (pressure differential type).

Stage Cementing collar structure:

The mechanical Stage Cementing collar consists of a collar body, a flexible plug, an open plug (gel plug or gravity plug), a pressure block and a closing plug.

Scope of application:

Gravity can be used to open the plug in straight or small-angle wells, and displacement plugs can be used in high-angle wells

Liner Hanger

Definition: The liner hanger is a special device used in oil fields to hang liners within an oil well.It suspends the liner pipe at the bottom of the upper casing string and performs cementing work.

Function:

• It can reduce the flow resistance of the replacement construction and is conducive to safe construction.
• It can save casing and reduce drilling costs.

Classification:

According to the type, it can be divided into three types: Mechanical, Hydraulic, Mechanical and Hydraulic.

Mechanical type can be divided into J-slot type and Rail type.

Liner hanger types as per structure classification

Liner hanger types as per Functional classification

Liner hanger giving tool

Liner hanger recycling tool

Outer casing packer

Definition: The outer casing packer is a device that is connected to the casing string and can form a permanent bridge between the casing and the naked eye annulus after the cementing is pressed.

Function:

• It can avoid the abnormal formation pressure or the cement ring during the infiltration of high oil, gas and water due to the weight loss of cement slurry.
• Effectively prevent the phenomenon of oil, gas and water sprayed outside the casing after cementing.

Classification:

According to the form of rising seal, it can be divided into hydraulic expansion type and oil-immersed water self-expansion type.

Outer casing packer structure:

The hydraulic expansion type casing outer packer is mainly composed of a rubber cylinder, a central tube, a sealing ring and a valve hoop.

Packer Types:Classification by means of packer seals

• (1) Self-sealing type: a packer that achieves sealing by the outer diameter of the sealed packing member (such as rubber rubber cylinder) (outer diameter of the cup) and the interference between the inner diameter of the casing and the working pressure difference.
• (2) Compression type: A packer that achieves sealing by the axial force compressing the outer diameter of the seal packing member (such as the rubber cylinder) to become larger (fitting the inner wall of the sleeve).
• (3) Expanding type: A packer that acts on the inner cavity of the packing member by a radial force to expand the outer diameter of the sealing packer to achieve sealing, and is also called a differential pressure packer on weekdays.
• (4) Combination type: a packer that is sealed by any combination of self-sealing, compression, and expansion.

Stop Collar (Location ring )(limit clamp, clamp)

It is used to fix or limit the centralizer.Can be divided into Slip on set-screw type,Hinged bolted Stop Collar,Spiral Nail Stop Collar

Cement umbrella

A cement umbrella is a device installed in the lower part of a graded cementing plant to prevent the cement slurry from sinking and supporting the pressure of the liquid column.

Pipe wiper

A device in which the scraper is installed outside the casing of the cement-sealed well section to remove the filter cake on the well wall to increase the cementation strength of the cement ring and the formation.