Fracturing proppant and the fracture conductivity

In the oil industry, in hydraulic fracturing ( hydraulic fracturing proppant )at the beginning, only natural quartz sand and is alwaysused as proppant fracturing material.

The 50's and 60's development of sand source and different flow capacity throughscreening, proppant conductivity , get higher.

The types, physical properties of proppant (size, intensity, sphericity, roundness, density etc.) and its distribution in the cracks, and crack closure pressure are the main factors controlling fracture conductivity.

The fracture flow capacity and fracturing material

The fracture ( fracturing proppants )flow capacity refers to the ability of crack conduction (delivery) of reservoir fluids, and with fracture proppant permeability (Kf) and crack of propped fracture width (Wf) of the product [KW]f to indicate.

  Many factors of master fracturing proppant physical properties and impact fracture flow capacity, is conducive to the rational selection of proppant, is conducive to the fracturing fluid with proppant fracturing material provides more exact requirements.

High efficient flow capacity of hydraulic fracturing

The so-called fracture flow capacity,( Hydraulic Fracturing Proppants ) refers to the product and fracture closed width and closure stress fracture permeability (wk) f[1 ~ 2].

  Proppant is the role of hydraulic fracture stimulation filling fracture initiation, which is no longer closed again, and the formation of a high flow capacity of the flow channel, keep the cracks open.

When encountering the crisis of water resources of shale gas

Shale gas rich area, is often the water resources are very poor area, such as according to the World Resources Institute data shows, China with the world's largest recoverable shale gas resources, but these resources are mainly distributed in the Tarim Basin, such as Sichuan Basin water resources is the lack of such a place, it can be said, China above 60% of recoverable shale gas resources are distributed in the more arid region.

  Of course, the same tragedy occurred in places such as Mexico, South Africa and other regions.

  Shale gas development will inevitably encounter the misuse of local residents living water, industrial and agricultural water use problems.

Shale gas well fracturing

Process for fracturing in shale gas, require the use of fracturing fluid and proppant, so it can produce cracks, and shale gas eventually exported to the ground storage.

In the drilling and fracturing stage, according to the World Resources Institute data display, a Shale gas  well needs 7000 to 25000 tons of water.

Each shale gas well’s water consumption

On the selection of fracturing fluid, there are three kinds of liquid nitrogen system, including direct injection, nitrogen foam injection and drag reduction of water. Cost, environment and yield and other factors to consider, at present the standard approach is the selection of fracturing fluid drag reduction of water, i.e. at high discharge pump into a large amount of water and a small amount of proppant and additives, to crack into deeper, improve the shale gas.

  Because the content of drag reduction in the water of the 99.5% water, so the technology is also known as the water fracturing. In the drilling and fracturing stage, according to the World Resources Institute data display, a Shale gas well needs 7000 to 25000 tons of water.

  And in the waste water recovery stage, probably only 70% of the waste water can be returned to earth for processing and storage, 30% of the water will be underground rock absorption.

Develop natural gas,adjust energy structure

According to estimates, Chinese oil consumption limit at 8 x 108t/a. Therefore, the task of the adjustment of China's energy structure will fall in the development of natural gas .

  This is the China's natural gas development opportunities, but also the natural gas industry must face the challenge. Although Chinese natural gas production in recent 10 years.

  The rapid growth, from 2000 272 * 108m3 to 968 * 108m3 in 2010, the yield increased 2 times, greatly increase proven reserves of natural gas, but compared to the Chinese energy consumption growth, natural gas in primary energy consumption structure.The proportion of growth is not obvious.

The proportion of natural gas in the energy structure

The overall situation of China's energy consumption is too heavy, high energy consumption, high emission( fracturing proppant ).

  To improve the Chinese energy structure, the first task is to reduce the proportion of coal in the primary energy structure, increase natural gas ,nuclear energy and other renewable energy proportion. According to the forecast of Chinese academy of Engineering in the long-term development of China's energy,
Oil production years our country long in 2 x 108t/a.

 Oil imports by various factors especially the influence of safety factors of,we must set the upper limit of oil consumption.

Driving force of Chinese energy structure for unconventional natural gas

Chinese energy structure makes the unconventional natural gas and conventional natural gas both must speed up the development of. Chinese structure of primary energy coal long-term high, the low proportion of petroleum, natural gas is not worth mentioning.

  In 2010, total energy consumption China up to 35 x 108 tons of standard coal equivalent, the consumption structure of coal accounts for 70%, oil accounted for 18%, frac proppant accounted for 4%, other 8%.