Adjei Stephen, Bageri Badr S, Elkatatny Salaheldin, Adebayo Abdulrauf
Department of Petroleum Engineering, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Saudi Arabia.
College of Petroleum Engineering & Geosciences, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Saudi Arabia.
ACS Omega. 2021 Feb 9;6(7):4793-4799. doi: 10.1021/acsomega.0c05699. eCollection 2021 Feb 23.
Conventional heavy-weight oil and gas well cement systems formulated with barite exhibit high viscosities. Additionally, the heavy-weight powder tends to settle, causing density variation and disruption in the porosity of the hardened cement cores. Studies have shown that such problems can be mitigated by controlling the particle size distribution of the cement system. The main objective of this study is to evaluate the effect of perlite powder particles on the fluid and hardened properties of barite-based cement systems. Barite heavy-weight cement slurries containing 0, 1, 2, and 3% by weight of dry cement (BWOC) of perlite powder were prepared. The rheological study was performed at a bottomhole circulating temperature (BHCT) of 150 °F and ambient pressure. An ultrasonic cement analyzer (UCA) and a high-temperature-high-pressure (HTHP) curing chamber were used to cure samples for 24 h at a bottomhole static temperature (BHST) of 292 °F and pressure of 3000 psi. Porosity measurements were performed using the nuclear magnetic resonance (NMR) technique. The results indicate that the incorporation of perlite powder into conventional barite-based heavy-weight cement slurry causes modifications in the properties of the systems. In general, the plastic viscosity decreases, while the yield point and gel strength increase with increasing perlite concentration. The reduction in plastic viscosity also reduces the pump pressure, while the increase in yield point and gel strength reduces particle sedimentation. Additionally, the compressive strength and tensile strength of hardened cement increase, while the wait-on-cement time decreases. NMR studies indicate that perlite reduces the porosity variation that exists in conventional barite-based cement systems due to the formation of stable cement systems.
用重晶石配制的传统重质油气井水泥体系具有高粘度。此外，重质粉末容易沉降，导致密度变化以及硬化水泥芯孔隙率的破坏。研究表明，通过控制水泥体系的粒度分布可以缓解此类问题。本研究的主要目的是评估珍珠岩粉末颗粒对重晶石基水泥体系的流体性能和硬化性能的影响。制备了含有0%、1%、2%和3%（基于干水泥重量）珍珠岩粉末的重晶石重质水泥浆。流变学研究在井底循环温度（BHCT）为150°F和环境压力下进行。使用超声水泥分析仪（UCA）和高温高压（HTHP）养护箱在井底静态温度（BHST）为292°F和压力为3000 psi的条件下将样品养护24小时。使用核磁共振（NMR）技术进行孔隙率测量。结果表明，将珍珠岩粉末掺入传统的重晶石基重质水泥浆中会导致体系性能发生变化。一般来说，随着珍珠岩浓度的增加，塑性粘度降低，而屈服点和凝胶强度增加。塑性粘度的降低也降低了泵压，而屈服点和凝胶强度的增加减少了颗粒沉降。此外，硬化水泥的抗压强度和抗拉强度增加，而候凝时间减少。核磁共振研究表明，由于形成了稳定的水泥体系，珍珠岩减少了传统重晶石基水泥体系中存在的孔隙率变化。
