Synthesis of Low-Density Heat-Resisting Polystyrene/Graphite Composite Microspheres Used as Water Carrying Fracturing Proppants

Abstract

Low-density heat resistamt, low-cost polystyrene (PS)/graphite microspheres were successfully synthesized via in situ suspension polymerization. Scanning electron microscopy (SEM) indicated that PS/graphite composite microspheres had good sphericity, and graphite particles were evenly dispersed in microspheres. Furthermore, density analysis illustrated that the density of composites was about 1.025-1.185 g/cm 3 with good suitability for carrying water. Thermodynamic testing revealed that the thermostability of the composite was dramatically improved by the introduction of graphite, which is used deep underground. In addition, the percentage of damage decreased to 1.3% with graphite ratio of 2.5% at 68 MPa. Therefore, PS/Graphite composite microspheres possess entirely feasible applications in oil exploitation as pure water carrying petroleum proppants.

Effect of π–π Stacking Interfacial Interaction on the Properties of Graphene/Poly(styrene-b-isoprene-b-styrene) Composites

“…Nowadays, graphene, a multifunctional nanofiller, has been revealed to be a promising reinforcing component for the construction of polymer composites [ 4 , 5 , 6 ]. To maximize the reinforcing efficiency of graphene in polymer composites, the issues of dispersion state and interfacial interaction between graphene and polymer matrix should be addressed [ 7 , 8 , 9 ]. Many methods were developed for the fabrication of graphene-based polymer composites, such as solution mixing, melt blending, and in situ polymerization.…”

Preparation of heat resisting poly(methyl methacrylate)/graphite composite microspheres used as ultra‐lightweight proppants

“…Meanwhile the perfect sphericity can improve the flow conductivity of proppant. 6,30 The acid solubility of PMMA/graphite composite microspheres was close to zero which was obviously better than quartz sand (4.59%) and ceramic (5.89%). The lower acid solubility illustrated the better stability of the proppant in an acidic environment, which means that the proppants could provide long-term conductivity.…”

“…37 However, because of the poor compatibility of graphite, this could lead to inhomogeneous distribution, poor adhesion, increasing brittleness of composites and the decreasing compressive strength as the proportion of graphite increased. 6,38 According to the literature, under the same condition, the fragmentation rate of quartz sand was 36% and ceramic was 10.2%. 39 Therefore, the traditional proppants may be replaced by composite microspheres which were more suitable as water carrying fracturing proppant.…”

“…5 The relative strength of these various materials increases with their corresponding apparent specific gravity (ASG), typically ranging from 2.65 g/cm 3 for sands to 3.4 g/cm 3 for sintered bauxite. 6 Difficult proppants transport and reducing fracture conductivity might be caused with increasing ASG. 7,8 More recently, ultra-lightweight (ULW) materials have been used as proppants since they reduced the required fluid velocity for proppant transport within the fracture, [9][10][11] which provided a greater number of fracture area to increase the fracture conductivity.…”

Application of polymers for coating of proppant in hydraulic fracturing of subterraneous formations: A comprehensive review

“…The aim of impregnation is coating of the internal web structure and filling the porous surface by using diverse types of polymeric coatings (Zhang, 2009). Polymers can fill pores with or without creation of surface coating (Han et al, 2014). Impregnation not only increases proppant's strength (Gaurav et al, 2012) but also add to the substrate the ability to be flexible and capable to absorb shock and stress without deforming (Li et al, 2012).…”