Research of oil fracturing ceramic proppant

Oil fracturing proppant is to make the deep stratum of rock fracture keep supports split state, its role is to support the two wall cracks, in order to make the pumping is stopped,

the crack to oil and gas wells in bottom hole pressure of eye drops to less than the closed pressure remains open.

Oil and gas injection well fracturing proppant ( ceramic proppant )is to improve the permeability of reservoir, increase oil production. Since 1947 the hydraulic fracturing technology in the American test success since 60 years of the development process,resin coated ceramic proppant proppant materials changed greatly.

Ceramic proppants acid resistance

The sintering temperature and fineness of raw materials have influence on the performance of high alumina ceramic proppants, under burning or over burning will cause the acid resistance, crush resistance reduction. The introduction of BaCO3 can significantly improve the performance of acid resistance of ceramic proppant.

  And with the increase of BaCO3 addition, acid resistance, continue to improve, but add too much BaCO3 can cause significant increase of broken rate, should control the amount of BaCO3 within 5.2%.

ceramic proppant structure densification

There is a great relationship between rate of crushing, acid solubility and the sample composition, sintering after the formation of barium feldspar is the main reason for the increase of the acid resistance. To generate a small amount of barium feldspar, can form acid liquid completely through Al2O3 in the intergranular phase protection layer, prompting theceramic proppant structure densification  , increase the acid resistant ceramics.

  When the addition amount of BaCO3 is too high, because the BaCO3 decomposition temperature is too high, the CO2 gas decomposition generated when it is difficult to rule out clean, the porosity increases, the effective area of the load reduction, stress concentration led to crush resistance variation. Therefore, when the amount of BaCO3 increases, celsian acid proof coating production also can increase accordingly, acid resistance will be increased, but the increasing porosity, will make the broken rate increased.

high aluminum ceramic proppants developed

Based on industrial Al2O3 as the main raw material, high aluminum ceramic proppant developed 

, the acid solubility of up to 0.75%, the mean crushing rate under 86MPa < 2.50%. Far more than the oil fracturing proppant industry standard requirements (acid solubility is less than or equal to 5%, 86MPa breakage rate is less than or equal to 10%).

  Fully meet the Tahe reservoir of super high pressure oil and gas fields of fracturing and acidizingrequirements.

The introduction of BaCO3 can significantly enhance the acid resistance of ceramic proppant

In order to further verify celsian on acid resistance, crush resistance effect, during the test,insulation 3H synthesis of barium feldspar under the temperature of 1560 DEG C with chemicalpure raw materials Al2O3, SiO2, BaCO3, and measurement of acid solubility and its breaking rate,the test results show that, the synthesis of barium feldspar acid resistance is good, the acid solubility of 1.15%, but crush resistance is poor, broken rate under 69MPa > 50%.

  This shows that acid barium feldspar is better, but the impact is very bad, the introduction of BaCO3can significantly enhance the acid resistance of ceramic proppant, but crush resistance will be reduced, industrial production, should control the adding quantity.

Effect of additive BaCO3 on ceramic proppant

During sintering, usually by additive to promote the sintering of ceramics, improve the structure, improve the performance of. During the test, found that the addition of -BaCO3 additive can greatly improve the acid resistance of ceramic proppant.

  Effects of BaCO3 addition on the ceramic proppant performance as follows .

The particle size of raw material on the ceramic proppants

In the sintering process of ceramics, the raw material of the finer particles, surface defects more lattice, more conducive to the increase of the sintering driving force.

  At the same time, a decrease in particle size can shorten the atomic migration and diffusion distance, accelerating the sintering process, thereby improving the compact degree of finished product structure, improving the performance of ceramic proppant.

Effect of sintering temperature on ceramic proppant

The firing temperature refers to the corresponding temperature to obtain the best performance of ceramic blank firing time, namely the firing temperature of fire stop.

  The firing temperature,frac sand direct effects of grain size and liquid phase composition and quantity as well as stomatal morphology and quantity.

  They influence the performance of integrated ceramic proppant. In the experiment, in order to sample 1 standard proportioning, ball milling 24h, respectively, at 1360 C, 1400 C, 1440 C, 1480 C under 1H sintering, thermal insulation,with the furnace natural cooling.

An important standard to measure the quality of the proppant

The apparent density ceramic proppant, acid solubility and broken rate is an important standard to measure the quality of the proppant fracturing fluid density, visual effects, acid solubility and broken rate effects of petroleum, natural gas output, were tested according to the oil and gas industry standard SYT5108-2006.
Apparent density (b) according to the formula, the acid solubility (c) according to the formula, the broken rate is according to the formula (d).

p = m2/V1                               （b）
M2 is the quality of the sample, the unit is g
V1 is the volume of the sample, the unit is cm3
p is density of samples, unit (g/cm3)



S = (m3-m4)/m3×100%                    （c）
m3, M4 as the quality of acid soluble, acid soluble samples before,
The unit is g, S is the acid solubility.

η=m5/m6×100%                          （d）
M5, M6 respectively fragmentation quality samples and proppant samples,
The unit is g, η for broken rate