Reservoir Evaluation and Development ›› 2020, Vol. 10 ›› Issue (3): 104-108.doi: 10.13809/j.cnki.cn32-1825/te.2020.03.016

• Comprehensive Research • Previous Articles     Next Articles

Research and application of high temperature low-density elastoplasticity cement slurry

PENG Jinlong,LI Quanshuang   

  1. Sinopec East China Engineering Technology Company, Yangzhou, Jiangsu 225000, China
  • Received:2019-04-04 Online:2020-06-26 Published:2020-07-03

Abstract:

In Ordovician of Tahe Oilfield, the bottom hole temperature is high, the seam hole is developed, the leakage easily occurs, and the annular clearance of cementing is small. Therefore, the conventional low density cement slurry system cannot guarantee the sealing integrity of cement sheath and meet the requirements of exploration and development. Aiming at the above difficulties, the modified fly ash is optimized to enhance the early strength of cement, the high anti-extrusion microsphere is compounded to improve the comprehensive performance of cement slurry, the high temperature elastoplastic material is optimized to reduce the elastic modulus of cement, and the low density elastoplastic cement slurry system is evaluated combined with the matching cementing additives. The density is applicable in the range of 1.25~1.50 g/cm 3, API water loss is less than 50 mL, the rheological properties is good, the right-angle is thickening, the cement slurry settlement stability is good, and the system has good mechanical properties. Meanwhile, the elastic modulus can be as low as 7 GPa and the compressive strength is greater than 14 MPa. All these things enhance the sealing integrity of cement sheath under the action of alternating stress. The applications of this system in well-Zhongtan-1 and well-TP193 of Tahe Oilfield are successful and the cementing quality are well, which indicate that the system can meet the cementing technical requirements of small clearance liner in the leaky formation of Ordovician and has a good application prospect.

Key words: cementing, high temperature, low density, elastoplastic, cement slurry

CLC Number: 

  • TE256