Process Introduction

Compared with conventional mode of operation, the coiled tubing acidification could facilitate the implementation of uniform acidification technology like fixing points, layering, steering, etc., distribute the acidizing fluid in long well sections, construct repeatedly and in multiple layers, conduct stimulation operations directly without well killing and flow back the reacted acid rapidly by gas lift after acidification so as to avoid the wellhead facilities, completion pipe string as well as the Christmas tree from contacting with the acidizing fluid and prevent corrosion, which is featured with high operation efficiency, cost-saving, convenience and time-saving, safety and reliability, etc.

Technical Indicators

Technical Applicability

This technology is applicable to acid pickling, acidification, organic plug removal and other stimulation operations for carbonate rocks and sandstone reservoirs.

Application

This technique is primarily used in carbonate reservoirs to realize acidizing fluid at fixed points in long horizontal section, and complete the dragging and acidizing operation by coiled tubing in open-hole horizontal well.

Well Name	Length of acidized well section (m)	Mode of completion	Yield before operations (cubic meter/day)	Yield after operations (cubic meter/day)
X-44H	164.5	Open-hole completion (with perforated pipe, but the perforated pipe are not run to place)	Shut down	579
Y-44H	160.28		Shut down	268
Y-29H	600.2	Open-hole completion	Shut down	596
X-46H	599.4		Shut down	577
X-57H	530.2		Shut down	655

Process Introduction

This technique is mainly to remove the paraffin precipitation of oil casing, organic scale of gum asphaltic and other pollutants at the immediate vicinity of wellbore, whose technical core is organic plugging remover system PA-OS3.

This system is featured with high efficiency (with asphaltene dissolution rate of 100%), environmental protection (free from highly toxic substances such as benzene, methylbenzene and xylene), safety (flash point >61℃), etc.

Technical Indicators

Technical Applicability

Remove the plugging at the immediate vicinity of wellbore, wellbore and pipeline caused by paraffin, gum asphaltic, etc.

Application

The supporting acidification has been applied on the site for more than 10 well-times, with obvious oil increment effectiveness.

Process Introduction

The viscosity of the clear self-diverting acid made by our Company is highly sensitive to the changes in PH and ionic concentration, and it could block off the high-permeability layer, lower down the reaction rate of acid-carbonate rock, and achieve the results of even acidizing fluid distribution; without polymers, it poses small damage to the formation.

Technical Indicators

Technical Applicability

Carbonate reservoir

Application.

The supporting acidification has been applied on the site for more than 10 well-times.

Process Introduction

The core additive of system is the gelatinizer, which could tackify the hydrochloric acid system within 25% effectively, and make the acidizing fluid system with better shearing and temperature stability through its tackability, thus lowering down the reaction velocity of acid-carbonate rocks and fluid-loss velocity and reducing the friction of pump injection effectively so as to pump successfully and make acidizing treatment in the deep section of the formation.

Technical Indicators

Technical Applicability

The gelled acid system is applicable to the acid pickling, acidification and acid fracturing technology in the carbonate rocks (calcareous) reservoir.

Application

This system is mainly used in the carbonate reservoirs of a number of overseas oilfields, and have been applied for more than 50 well-times cumulatively in acidizing operations.

Process Introduction

The product PA-VERT is a new additive for stimulation with multiple functions integrating the wetting reversal, unlocking of water lock, inter-solubility, iron stabilization, blistering, cleaning and other features, which has been widely used in acid pickling, acidizing, acid fracturing, unlocking water lock and other working solutions of plug removal for oil-water wells of sandstone and carbonate reservoirs, with the maximum operating temperature up to 160℃.

Technical Indicators

Technical Applicability

The product PA-VERT is a new additive for stimulation with multiple functions integrating the wetting reversal, unlocking of water lock, inter-solubility, iron stabilization, blistering, cleaning and other features, which has been widely used in acid pickling, acidizing, acidizing fracturing, unlocking water lock and other working solutions of plug removal for oil-water wells of sandstone and carbonate reservoirs, with the maximum operating temperature of up to 160℃.

Application

From 2013 till now, PA-VERT has been applied for more than 100 well-times cumulatively in acidification and acid fracturing operations for the oilfields in the Bohai Sea, the Western South China Sea as well as overseas oilfields, and has obtained better stimulation and injection stimulation efficiency, achieving significant effect in cost decreasing and benefit increasing. In recent years, the multi-purpose wetting reversal additive has been used to remove the plug of the oilfields resulting from the pollution that is caused by leakage and loss of drilling fluid and work-over fluid, which has proved to have significant efficiency in plug removal.

Process Introduction

PA-SAS is an antiswelling/shrinkage agent of dual-polyquaternary ammonium salt, which not only has better anti-swelling performance, but also has better shrinkage performance as well as better compatibility with acidizing fluid.

Technical Indicators

Technical Applicability

This agent is used in anti-swelling treatment, acidification and acid fracturing operations as an additive.

Application

It has been used as the additive for acidizing for more than 12 well-times; used for 2 well-times in anti-swelling operation and treatment, with average apparent water injectivity index increased from 22m³/(MPa•d) to 30m³/(MPa•d), and has significant efficiency in decompression and augmented injection.

Process Introduction

This product refers to Mannixi alkali-type acidizing corrosion inhibitor, which is well compatible with hydrochloric acid, multi-hydrogen acid and fluoboric acid and other working solutions, and could satisfy the requirements of reservoir acidizing operations at 180℃.

Technical Indicators

Technical Applicability

The ultra-high temperature acidizing corrosion inhibitor is widely used in acidizing and acid fracturing operations at more than 160℃.

Application

It has been applied for more than 10 well-times as an additive of acidizing corrosion inhibitor.