摘要
为满足四川油田高压天然气井固井对水泥浆＂压稳、替净、封严＂的要求,选用高密度（5.05 g/cm3）、过孔径为74μm筛的精制铁矿粉作加重剂,并调整了其粒度分布,优化了干灰组分比例,确定了最优水灰比（0.29-0.35）;同时通过多种水泥外加剂优化组合（SD18、SDP-1、SD35、SP）来调整高密度水泥浆性能,实现了水泥浆流变性、稳定性和抗压强度3者相协调,使水泥浆具有良好的动态和静态特性,研制出了密度为2.10-2.40 g/cm3的高密度水泥浆。该水泥浆API失水量小于50 mL,流变性好,稳定性高,SPN值小于3,有较好的防气窜性能,稠化时间可调,水泥石早期强度大于14 MPa。该高密度水泥浆体系在龙岗61高压天然气井中进行了应用,一次性成功封固4 065 m的井段,评价结果表明,其优质率为43.75%,中等质量井段占42.13%,单井合格率达85%以上。
A refined high density iron-ore fine(density 5.05 g/cm3,particle size ≤ 74 μm) is used to weight cement slurry in high pressure gas wells in Sichuan.The particle size distribution of the iron-ore fines was adjusted for better flow behavior of the slurry.By optimizing the water : cement ratio(0.29～0.35) and the composition of the slurry,a cement slurry of excellent rheology,stability and compressive strength was obtained.Cement slurry having density between 2.10 and 2.40 g/cm3,FLAPI< 50 mL and SPN < 3 was formulated.The cement slurry had stable rheology and adjustable thickening time.The early strength of the set cement formed by the slurry was greater than 14 MPa.A formulation of the slurry was successfully applied in well Longgang-61 for cementing a section of 4,065 m of the hole,and good cementing quality was obtained.
出处
《钻井液与完井液》
CAS
2009年第6期43-46,共4页
Drilling Fluid & Completion Fluid
