Through-tubing Technology and Tools

Due to the progress of the production process of rubber tube, the performance of rubber tube is still gradually improving and developing. It can be setting in the casing or in the naked hole, either in a straight well or in a horizontal section, either in the conventional hole or in the key seated hole.

A series of expansion tools were developed.

• Series 1: expansion bridge plug;
• Series 2: expansion packer;
• Series 3: expansion type cement holder;
• Series 4: through the tubing series.

In all the series of tools, there is also the difference between permanent and recyclable.

Specifically derived into a series of tools:

• K 341 packer;
• K 344 packer;
• OL-K naked hole bridge plug;
• OL-TT through tubing bridge plug;
• J-type cement retainer.
• And its various auxiliary tools

TT-Tubing technical introduction

Introduction of oil tubing technology

The through-tubing expansion bridge plug comes in two basic sizes. One is the rubber tube and its bridge plug over 2-7 / 8 “tubing with an outer diameter of 56-58m m. One is rubber tube with an outer diameter of 62-70mm can be sealed through a 3-1 / 2 " tubing. The formula of the through tubing bridge plug is slightly different from that of the ordinary expansion packer. The rubber formula by the special process can make the rubber tube have greater expansion and good sealing performance. It can be used for the through tubing bridge plug. The size of the common through tubing bridge plug is 56mm outer diameter rubber tube can be sealed over 62 oil pipe in 5-1 / 2 "casing or 7" casing. The 68mm rubber tube can be sealed over 3-1 / 2 "tubing in 5-1 / 2", 7 inch casing. Only different sizes of the casing setting sealing pressure capacity are different. Often can pass through the tubing, such as 1.5 "tubing, through 2-7 / 8" tubing sitting in 5 "or 5-1 / 2" casing to complete the seal.

The basic configuration of the pipe plug string:

• Coil tubing connector;
• Coil tubing double disc return pressure valve;
• Mechanical release (used as an emergency release)
• Automatic filling valve; (keep inside and outside connection when drilling, prevent the coil tubing from being damaged by extrusion)
• The bridge plugs access tools;
• Bridge plug

Characteristic

Large expansion rate;

Through tubing operation;

Coiled tubing feeding;

Usage occasion

Naked hole blockage;

Cover transformer well blockage;

Horizontal section blockage;

Screening section blockage;

Bore hole section blockage;

Other blocking

TT-Tubing technical introduction

Technical parameter

Each tool introduction

1. Automatic filling valve

Automatic filling valve is an automatic balance valve. There are two roles. The first is when the coil tubing goes in, automatically balance the internal and outer level of the string and its pressure. Prevent the tubing from being out.

When need to setting the bridge plug, throw the ball and suppress to setting the bridge plug.

2. Bridge plug access tool

The bridge plug access tool is specially designed for the laying down the bridge plug. The access tool varies according to the structure of the bridge plug. Access tool of through tubing adopts detent engagement, fixed down the well. The dropped bridge plug joint can facilitate the salvage of the bridge plug!

After the plug is setting, the release pin into the tool will bear the internal pressure of the string. When the design pressure is reached, the pin is cut, the piston moves down, and the bridge plug is released, wellhead pressure decreases.

When the bridge plug needs to be recovered, use the GS salvage tool to directly salvage the salvage neck of the plug. Salvage out of the bridge plug.

3. "GS" overshot

The "GS" overshot is the standard fishing tool. Selection is based on the shape and size of the fishing neck.

Drop down directly and engage with the fishing neck. The bridge plug can be pulled above. (If it's an unsealed bridge plug )。

If the existing string cannot pulled out the bridge plug after engagement, must remove the GS overshot. Take out the fishing string.

"GS" is a refundable fishing tool.

4. Introduction of the expanding bridge plug

The through tubing expanding bridge plug is a hydraulic expansion filling sealing packer assembly. There are permanent bridge plug and recyclable type.

The recyclable bridge plug is divided into direct bridge plug and indirect bridge plug.

Direct unsealed bridge plug due to the pressure on the lower part of the plug, the design of the pin force must be consider the differential pressure under the plug. To avoid the top force unsealed the bridge plug;

The indirect release of the plug so that the force on the plug does not act on the shear pin.

Ensure the sealing and work of the bridge plug. When unsealing is required, lift the joint above, The pin will be stressed.

The internal balance valve ensures that the bridge plug is unsealed first balance, to ensure that the internal and external pressure difference is consistent. Unseal again.

The lower puller can protect the bridge plug from the friction of the outer diameter damage when go into the large slope well

5. The introduction of the continuous oil pipe pouring ash tube

Coil tubing ash pouring pot is a tool used to match the coil tubing through the tubing bridge plug. After the bridge plug is settling, it is often needed pour ash to increase the pressure capacity of the bridge plug. Ensure the smooth operation of the lower part. There are two ways to open the ash cylinder, one is the switch when the pressure, one is the switch. It can also be turned on by action.

After opening, the direct pressure pushes all the cement out of the inverted ash cylinder. Operating steps:

1. Conduct exhaust pressure test on the rubber cylinder of the bridge plug in the workshop before entering the well. Cover the steel pipe with 4-10mm greater than the rubber drum. After the exhaust, press down by 2-5 Mpa. (Do not remove the rubber cartridge again)

2. Connect the bridge plug and supporting tools into a string, go into the wellbore, and slowly when reaching the target layer

3. Confirm the depth of insertion

Throwing the ball

4. Suppress setting bridge plug.

5. The sealing pressure of the bridge plug continues to press up. Shear pressure of the delivery tool to reach the bridge plug 6. After cutting the tool, the bridge plug is sealed. Delivery tool and bridge plug removal. The pressure on the ground is instantly released to zero. Remove the plug and send it into the string