油基岩屑残渣自悬浮支撑剂的制备及性能评价

Preparation and performance of self-suspending proppant with oil-based drilling cuttings pyrolysis residues

关键词:  油基岩屑热解残渣  陶粒支撑剂  聚丙烯酰胺  膨胀性能  自悬浮 

Key words:  pyrolysis residues of oil-based drilling cuttings  ceramic proppant  polyacrylamide  expansion property  self-suspending

摘要:

目的 为了安全有效地处置和利用页岩气开采过程中产生的油基岩屑残渣,采用其烧结陶粒支撑剂,同时,为提高支撑剂在清水中的悬浮性能、改善支撑剂在裂缝中的分布、简化压裂施工工艺、提高压裂增产效果,进行了自悬浮支撑剂的制备与研究。方法 通过聚合反应将聚丙烯胺树脂包覆在支撑剂表面,制得膨胀型自悬浮支撑剂,研究了交联剂用量、单体量、合成温度对自悬浮支撑剂膨胀性能的影响。结果 覆膜材料配比(质量比)为:m(陶粒)∶m(丙烯酰胺)∶m(N,N′-亚甲基双丙烯酰胺)∶m(过硫酸铵)∶m(N,N,N′,N′-四甲基乙二胺)=10.000∶2.000∶0.002∶0.020∶0.031时,自悬浮支撑剂性能最佳,其膨胀倍数为4.3,沉降速度为45 mm/s。结论 覆膜支撑剂自悬浮功能的实现主要与聚丙烯酰胺树脂的溶胀有关,树脂的体积膨胀和聚丙烯酰胺分子链向外延伸引起溶液黏度的增加,提升了支撑剂在溶液中的沉降阻力。该研究对拓宽油基岩屑烧结支撑剂的应用范围、提高油基岩屑残渣资源化利用产品附加值有十分重要的意义。 

Abstract:

Objective To dispose and utilize pyrolysis residues of oil-based drilling cuttings (PRODCs) during exploitation of shale gas safely and effectively, original ceramic proppants were first prepared by sintering the pellets using PRODCs as a raw material. In order to improve the suspension performance of the proppants in water and the distribution of proppants in cracks so as to simplify the fracturing process and enhance the effect of increasing production, the surface characteristics of this ceramic proppant was modified to achieve self-suspending. Methods Polypropylene amine resin was used to coat the surface of proppant by aqueous graft polymerization during the modification. The effects of the content of crosslinker and monomer as well as the synthetic temperature on the properties of polymer-coating proppants were discussed. Results When the weight ratio of ceramic proppants, acrylamide, N, N′-methylene bisacrylamide, ammonium persulfate and N, N, N′, N′-tetramethylethylenediamine was controlled at 10.000∶2.000∶0.002∶0.020∶0.0310 respectively,the prepared self-suspended proppants could achieve optimal self-suspending performance with swelling ratio of 4.3 and settling velocity of 45 mm/s. Conclusion sThe realization of self-suspending function for proppant is related to swelling of polyacrylamide. During the modification process, the settling resistance is brought by the expansion of polymers and viscosity increase of solution due to the extension of molecular chain of polyacrylamide. It is of great importance to enhance the functional properties of ceramic proppants with PRODCs and increase the additional value in the recycle utilization of the wastes.