Different at ceramic proppant stages of the design process requirements and fracturing

Depending on the different stages of the natural gas fracturing requirements and the fracturing process , the fracturing fluid may be used in a construction of a liquid containing various additives . For the vast majority of the total amount of liquid fluid and sand carrying fluid front , should have a certain force and to create cracks in the wall joints and cracks after fracturing sand filling has sufficient conductivity . So they must have the following properties:

① filtration small . This is made long slit , slit width important performance . Hydraulic Fracturing Proppants filtration , primarily depends on its viscosity, formation fluid properties with walls made of fracturing fluids , high viscosity fluid loss is small . Add in the fracturing fluid fluid loss agent can greatly improve build walls to reduce fluid loss . When fracturing , requiring pre- liquid , liquid integrated carrying sand filtration coefficient ≤ 1 × 10-3m/min1/2.

② suspended sand ability. The ability of suspended sand fracturing fluid mainly depends on its viscosity. As long as the fracturing fluid has a higher viscosity, in which the sand can be suspended , in which the distribution of sand seam is very advantageous. However, the viscosity is not too high , if the viscosity of the fracturing fluid is too high, the height of large cracks , is not conducive to produce a wide and long cracks. The viscosity of the fracturing fluid is generally considered as 50 ~ 150mPa · s suitable. Table 3-1 visible liquid viscosity directly affects the size of sand settling velocity .
③ low friction . The fracturing fluid in the pipe friction increases, the slit made for the smaller horsepower available water . Friction is too high , it will greatly improve the wellhead pressure , reduce construction emissions , construction and even cause failure .
④ good stability . Fracturing fluid thermal stability , including stability and shear stability. That fracturing fluid at elevated temperatures , mechanical shear viscosity does not occur significantly reduced, which plays a key role in the success of the construction .

Fracture Heightgrowth controlling technique

When the oil and gas layer is very thin or middle layer and the shielding layer between the minimum horizontal main pressure difference is small, the crack pressure height to easily enter the shielding layer, when the need to control the natural gas fracturing heightextension. Can be realized by controlling the Proppant fluid performance parameters and construction displacement, the more reliable is the artificial interlayer fracture Heightgrowth controlling technique.

The basic principle is in the pre adding liquid floating or sinking type guide agent,through the front fluid into the crack, floating guide agent and sink type guiding agentrespectively, floating and sinking gathered at the top and bottom of artificial fracture,low permeability formation compaction artificial barrier, prevent crack pressure upward/ downward propagation, reach the fracture height controlling purpose. In order to make the two guide agent can move up and down, usually in the injection with guiding agent liquid short-term after the pump stops, then the fracturing operation normal.

Artificial interlayer fracture height controlling technology is mainly used to 1) bulkhomogeneous formation production layer and non production layer interbed; 2)production layer and between layers of water gas, good interlayer; 3) production layer and the shielding layer stress difference can not effectively control the cracks ofvertical extension.

High strength proppant fracturing of oil

With the rapid development of the world oil industry, oil and gas extraction is gradually increasing difficulty, the depth of oil and gas wells deeper, low permeability deposits more and more domestic and foreign high-strength proppant products The demand is also growing. Most domestic manufacturers only produce medium and low intensity of the product, and inconsistent quality, only a small number of enterprises in Guizhou and Jiangsu capable of producing small amounts of high-strength products (less than 12,000 tons), and low product technical performance, the main reflected in the long-term diversion permeability and the ability to quickly decay under high pressure, it is difficult to meet the needs of deep oil and gas exploration.
Our products are mainly dependent on imports of high-strength, global demand for high-strength high crush proppants of over 600,000 tons. Currently, the international market in the production of high strength bauxite proppant fracturing leading level in the United States CARBO company, its products under the crushing rate ≤5% in 69Mpa pressure, and quality of our products has been able to reach ≤5%, its at the same level Under pressure 86Mpa broken rate ≤9%, the technical level of the leading domestic, close to the international advanced level.
US China Ceramic Proppant LTD is engaged in a global proppant conductivity sales of the company, after years of development, has mastered mature production technology and processes, and has developed a low-density, high-strength technology and oil fracturing proppant suppliers production process. To further occupation of foreign markets, the company's investment environment through Guizhou Province conducted an investigation, in June 2005 in Guiyang City, Guizhou Province Xiuwen County was established in pottery proppant (Guizhou) Co., Ltd., for high strength proppant fracturing of oil investment product development and production.
Ceramic china proppant in (Guizhou) Limited a total investment of 13.12 million yuan project, the establishment of an annual output of 20,000 tons of oil proppant production lines and expanding product size, development of new products, the company's products, technology and services in the domestic oil support advanced level agents processing industry, as domestic oil ceramic proppant manufacturers enterprises. After the project is put into operation, the annual sales income of 42.9 million yuan is expected to total annual average profit of 15.093 million yuan, the annual average 8.301 million yuan turned over to state taxes. After the implementation of this project, can replace imported products, save a lot of foreign exchange for the country. At the same time as the product not only of good quality, to more advanced international level, but the origin has a wealth of resources, low production cost, highly competitive in the international market. Project advantages mainly in the following aspects:
1,the main producing areas of Guizhou bauxite, convenient source of raw materials, with the world's other manufacturers can not match advantage;
2,the parent company of the project implementation unit of the United States --- China Ceramic Proppant LTD engaged in the sale of oil proppant, has acquired a large number of foreign customers, the first batch of products exported by the company to complete, 70% of the domestic exports carried out by the company;
3,due to the optimization of the formulation and process path, capital investment in the equipment a lot lower than peers, while significantly reducing the consumption of raw materials, compared with other domestic and foreign manufacturers have a large production cost advantage;
4.Petroleum frac proppant products currently in its infancy in the country, and foreign company's product sales price is too high, the country's high-production costs, inconsistent quality, so the company's products have broad market potential and strong market competitiveness;
5,corporate team only has better technical development capabilities, but also has abundant experience in corporate management. By US China Ceramic Proppant LTD provides strong backing for the company's development. Meanwhile, the corporate team has long experience in foreign trade of petroleum ceramic proppant products, with abundant resources and stable trade customers, compared to other domestic manufacturers have obvious advantages in terms of sales channels.

Production of ceramic proppant should note the following seven elements

In this paper, the main raw material level bauxite, dolomite, boric acid, bentonite, precipitated barium sulfate as a secondary raw material to manufacture Ceramic proppants, investigated the effect of addition of various raw materials for proppant performance. The results show that the ratio of raw materials through the rational design of improved granulation process and select the appropriate firing temperature can develop excellent performance ceramic proppant. After industrial production practice, confirmed that the design of the production process is feasible. Study the following conclusions:
(1) According to the Al203-Si02 binary phase diagram, select the level of bauxite-based raw material, adding a certain amount of auxiliary materials can produce excellent performance of ceramic proppant, the process parameters are affordable range of company equipment within;
(2) silica powder because small particles can be effectively filled in the gaps between the bauxite and other fines, in the firing process, due to their activity, is conducive to reduce the sintering temperature, while an appropriate amount of silicon powder also help to improve performance;
(3) is introduced in the form of barium sulfate, barium oxide, barium carbonate and the effect of the introduction of barium oxide can be increased as the strength of the proppant. When the amount of barium sulfate 超过 5 lnj weak s%, the intensity decreases sharply, so the amount should not exceed 5 m weak s%;
(4) Add 2 mass% of dolomite, can effectively reduce the acid solubility, but also can reduce the sintering temperature, play to save energy, reduce the cost of action. Bentonite is introduced to increase the strength of semi-finished products, reducing the ash off phenomenon during storage and transportation process, you can drop ring formation is only the chance to improve the pass rate;
(5) By comparing the various methods on Oil fracturing proppant granulation performance, designed a new granulation process. First, the new technology is the traditional spray drying equipment to do the following improvements:
I) will be expanded to the hole diameter piece 2.5-2,8 mm:
II) The non-porous flat plate to 2.8-3.0 mm perforated cover:
The improved slurry discharged after reducing the shear rate to give a smaller spray angle and increase the droplet diameter, to obtain a better particle. By controlling the water content in the slurry, while optimizing the spray drying parameters, can greatly improve the appearance and quality of the particles, not only a uniform particle size, but also eliminates the center due to the rapid evaporation of water vapor generated enormous pressure to form a fracture surface of the particles cavity; good sphericity particles, greater density (1.2-1.3g, cI113). But still relatively rough surface of the particles, but also close enough, on this basis, select the sugar coating machine treatment processes and achieved good results;
(6) the density and particle size of the raw material have a certain impact on the performance of the proppant, especially some larger particle size effects. Raw material particle size of 0.004 mm obtained proppant strength higher than the particle size of 0,01 mm of 80--90%, the particle the higher the density the greater the strength;
(7) the firing control Proppants for hydraulic fracturing an important part of the final performance, in order to prevent burning and burnt due to the occurrence, the firing temperature must be strictly controlled. In this study, the ratio of the material, the optimum firing temperature of 1360 ± 5 ℃, so that one can guarantee the quality of products, on the other hand can greatly improve the pass rate.

Quartz sand has the following characteristics

Natural quartz sand is used in the first and widespread natural gas fracturing ( about 55% ) , the main chemical composition is silicon oxide (SiO2), while with a small amount of aluminum, iron, calcium, magnesium, potassium and sodium compounds, and a small amount of impurities . Quartz content is an important indicator of the quality of quartz sand , quartz content of quartz sand fracturing is generally about 80% ; quartz content of foreign high-quality quartz sand up to 98% .
Quartz sand has the following characteristics:
( 1 ) sphericity of the quartz sand is preferably broken, still maintain a certain conductivity .
( 2 ) a relatively low density of the quartz sand , to facilitate pumping .
(3) 0.154mm ( ie 100 mesh ) or fine sand can be used as a natural crack down fracturing fluid filtration agent , filling cracks in oil fracturing proppant with the master .
Lower ( 4 ) the intensity of quartz sand and began crushing pressure of approximately 20MPa, fragmentation will greatly reduce permeability, but also by embedding, fines migration , congestion, fracturing fluid and non- Darcy flow effects of injury , fracture conductivity can be reduced to below 10% of the initial value , and therefore suitable for low pressure reservoir is closed .
( 5 ) the price is cheap, you can make the best in many areas . Origin of fracturing with quartz sand wide , such as Lanzhou sand, sand , Fuzhou , Fujian , Hunan Yueyang sand.

The performance of the ceramsite sand related knowledge

According to the light aggregate and the test method of GB/T 17431.1-1998 new standards, Gao Jiangtao sand refers to the structure strength of symbols is not less than 25 mpa with light coarse aggregate. Their level of technical requirements in addition to the density, label tube pressure strength, strength, bibulous rate is a specific index, other indicators (grain size distribution, softening coefficient, grain shape coefficient, harmful substance content, etc.) the same as the super light, general ceramsite. Large production Gao Jiangtao when yield, low energy consumption, high added value, sales price super light natural gas fracturing ceramsite, ordinary high 50%. Prepared with ceramic proppants Jiangtao grain of high grade and prestressed lightweight aggregate concrete must be homogeneous. High performance ceramsite sand is refers to the high strength, bibulous rate is low, density smaller roasting or unburned ceramsite. Light aggregate is rich in resources, wide variety. It has natural lightweight aggregate, solid waste light aggregate and artificial light aggregate. According to their formation conditions and performance point of view, can be used in the preparation of high performance concrete only through special processing of high-performance ceramsite.