High Performance Shape Memory Epoxy Syntactic Foam Composites as Lost Circulation Material in Deep Drilling

• Published in: Macromolecular materials and engineering 2024-03, Vol.309 (3), p.n/a
• Main Authors: Ma, Qian, Ren, Mingwei, Wang, Chao, Xing, Xijin, Liu, Lianying, Yang, Wantai
• Format: Article
• Language: English
• Subjects: Bisphenol A; Castor oil; Compression ratio; deep drilling; Diamines; Drilling; Glass transition temperature; high performance; High temperature; Impact strength; lost circulation materials; Microspheres; Plastic foam; Plugging; Recovery; Shape memory; shape memory epoxy polymer; syntactic foam; Syntactic foams; Temperature; Tensile strength; Thermal stability
• ISSN: 1438-7492; 1439-2054
• DOI: 10.1002/mame.202300303

Lost circulation is a critical issue in drilling. This work reports the investigations on shape memory epoxy polymers (SMEPs) with high switching temperatures, and good thermal, mechanical and shape memory properties for plugging in deep drilling. The SMEPs are produced by curing diglycidyl ether of bisphenol A (DGEBA) and castor oil glycidyl ether (COGE) with a flexible poly(oxypropylene) diamine (D230) and a rigid 4, 4′ ‐diaminodiphenyl methane (DDM). Increasing D230 contents or using COGE, glass transition temperature (Tg, 93–163 °C, DMA analyses) and crosslink density of SMEPs are reduced, shape recovery rate is increased, while tensile strength, elongation at break and impact strength are improved. Further, shape memory epoxy syntactic foams (SMEFs) with high‐temperature adhesion are developed by introducing polymer microspheres into SMEPs. The SMEFs have compression ratio of 52–58%, and expansion ratio of 100% by adding 2% wt. microspheres. They retain the Tg and thermal stability of SMEPs, and show a delayed, slower recovery than SMEPs. Long fracture plugging experiments exhibit that a pressure‐bearing capability of 8.99–9.81 MPa is achieved with SMEFs in sealing fracture slots at a high temperature. Shape memory epoxy polymers (SMEPs) with high Tg, good thermal and mechanical properties are produced and corresponding syntactic foams (SMEFs) are developed for plugging in deep drilling. The expansion and release of recovery stress, high modulus in rubbery state, and adhesion of SMEFs contributes to effective bridging of lost control materials, and high pressure‐bearing capabilities in fracture zones.