Introduction

Technological introduction

As the frontier technology at home and abroad, CO₂ dry sand fracturing technology is an important new technology to replace water-based fracturing to solve the fracturing problems of unconventional oil and gas reservoirs such as shale oil and gas, such as low efficiency, great harm and adverse to reservoir protection and environmental protection, and an important direction for reservoir stimulation and reconstruction in the future. However, traditional pure dry airtight

fracturing is limited by special equipment and high cost of airtight sanding. The company's latest new technology of atmospheric pressure quasi-dry carbon dioxide fracturing and its new product integration self-crosslinking emulsion fracturing fluid thickener APFR-6 and liquid CO₂ high-efficiency anti-drag APFR-2, as the latest solution to solve related problems, make large- scale application of CO₂ dry fracturing technology possible.

Main technical features of the new technology:

1. A small amount of water with normal pressure sand-carrying fluid: a small amount of water (10-30%) is used to continuously prepare sand-carrying fluid under normal pressure by using APFR-6 online and pre-adding APFR-2synergistic thickening.

2. High sand content and sand ratio: APFR-2 rapidly thickens in liquid CO₂ and forms a high- viscosity mixed emulsion with water-based sand-carrying fluid. The comprehensive viscosity can reach up to 80mpa.s, and the sand ratio after mixing is up to 40%.

3．Drag reduction and excellent carrier: suspension ability, resistance to temperature 160℃, shearing, drag-reducing rate above 70%.

4. Low or no damage: a small amount of water is soluble with saturated CO₂, as in the pure dry method, avoiding water sensitivity and water lock injuries.

5. No need for special equipment such as airtight mixed sand tank: able to increase energy fracturing can be used for dry atmospheric pressure quasi-dry fracturing, and the effect of sand- carrying fracture making and increasing production will be greatlysuperior to energy fracturing.

6. High cost performance: relatively low amount of liquid CO₂, only two agents, APFR-6and APFR-2. The new technology and new products have been successfully applied in an oil field in northern shanXi. After conventional fracturing in adjacent Wells and adjacent blocks, no gas can be produced. After fracturing by the standard dry method under normal pressure, it is estimated that there will be an unimpeded gas production of 100,000 m³/day, and the effect of production increase is very excellen.Currently, the company has been promoting and popularizing major oil and gas fields in China, especially shale oil and gas fields and North America and Russia. The annual construction will exceed 1,000 Wells, the output value will exceed 1 billion, and the development of related industries will be driven. The technical and economic prospects are very broad.