Effectively increase the high conductivity proppant fracturing strength

Despite the high closing pressure to adapt to the direction of the deep hypotonic development and application of high-performance, high-quality, high conductivity  Proppant  artificial, but further development of proppant technology research, and its development trend is mainly the following aspects .
1. Developed in intensity or high-strength low-density sintered ceramic
Although the current artificial ceramic with high strength characteristics, but relatively higher density particles of fracturing fluid properties and pumping conditions are put forward higher requirements, so the research and development of medium-intensity or high-strength low-density sintered ceramic will is an important direction of development.

(2) improve fracture conductivity of the surface modifier technology
The use of a surface modifier, its active ingredient is a polymer, when it is added to the aqueous-based fluid when the proppant pack can quickly attached to the support agent, which is a stable molecule resistant to acid erosion and corrosion resistance treatment agent. Surface modifier as a liquid additive in  Hydraulic fracturing  process of adding to the water-based fracturing fluid, it can quickly proppant pack as a thin stick on the skin. Obtained using a surface modifier following results:
(1) the surface modifier to improve the particle surface friction, the support agent in the fracturing fluid to increase the settling time, and ultimately reduce the density of the filling layer after deposition, thus improving the fracture proppant the vertical distribution, increasing the cross-brace fracture height, increasing the filling layer porosity and permeability.
(2) fine particles within the proppant in the fracture generated in the process and the fine particles are fixed to the cladding surface modifier to reduce the pore space of small particles clogging opportunity to improve the yield of fixed small particles is an important factor in the effectiveness of measures , the formation of fine particles to produce a particular.
(3) the surface modifier coated on the proppant, the fracturing fluid gel to prevent proppant adsorbed to the surface, thereby enhancing the viscosity of the gel breaker reduces the efficiency of the fracture more easily be cleaned, thereby improving fracture crossing the flowback rate.
(4) Since the friction resistance between the high proppant and viscosity, the more difficult to move the proppant proppant reflux under control, especially for the forced closure construction can improve the fracturing fluid flowback rate.

3. Applications developed hollow or porous low density proppant
In order to meet the technical requirements of low density can be proppant pellets can be made hollow, porous spherical particles (beads uniformly dispersed through interconnected micropores), for the hollow spherules, once hollow size exceeds the threshold, the inner surface will produce stress limit, the hollow space of the diameter is increased further, the pressure will reduce fragmentation.
Production of pores having a uniform porous spherical particles easier than the manufacture of hollow spheroids, optimal selection of high purity aluminum material can be, mullite ceramics and high strength, density 1.8 ~ 2.5 g/cm3. Production method is the small thin-walled hollow spheres release fluidized bed spray drying, put several of these together into larger pellets sintered pellets, and then coated with a hard foreskin package sintered pellets. Produced in this way can its density sintered bauxite sand close, but keep a high strength.

4. Double resin coating technology
The inner layer is pre-cured film, and the outer layer is cured coating, pre-cured resin film, the inner layer of the buttress material to provide additional strength, the outer cladding put curable resin particles together, so that the increase in proppant The advantages and its own strength proppant consolidation combine the advantages. Reasonable cost can proppant high strength, low density, and the ability to permanently bonded together. Inner layer resin film has undergone heat treatment, representing the advance of the polymerization process, thus improving the particle strength, cladding layer is a very thin layer of curable tree in order to use the well temperature and fracture closure pressure, the fracture may be formed in the solid Results multilayer proppant pack.
Can be any curable resin coated particle fragmentation, the resin film is thin, so that the fracture of the contact pressure so that they can be bonded together to form a larger width of the filling layer, this support agent might be the only proppant is not embedded in the formation. At low temperature (below 54 ℃) producing layer, the need for a catalyst to start and accelerate the consolidation of the resin film.
Comparative tests showed that anti-closure pressure, 69 MPa and 149 ℃ conditions, resin-coated proppant is not broken rate as high as 6% or more, under the same conditions, the resin coating layer is also not crushed proppant. At 69 MPa and 149 ℃ conditions, the test surface, the resin coating layer of any type of thrust agent are quite stable branch. Higher temperatures can increase the resin coating layer strength  Proppant ，  and for a variety of ceramic, high-temperature reducing their strength. Resin coating layer strength proppants than almost all of the resin coated proppant is not all large, and the intensity with increasing temperature difference becomes more apparent. It can be successfully applied to 7 600 m deep underground reservoir and 315 ℃ temperature. However, the proppant fracturing fluid and oxidizer with alkaline incompatibility, should strengthen its wrapping material compatibility studies.