HFY 油田高压盐膏层固井技术

Cementing technology for high-pressure salt-anhydrate bed in HFY Oilfield

聂臻 许岱文 邹建龙 齐奉中

NIE Zhen XU Daiwen ZOU Jianlong QI Fengzhong

中国石油勘探开发研究院，北京　100083 中国石油伊拉克地区公司，迪拜　500486 天津中油渤星工程科技股份有限公司，天津　300451 中国石油钻井工程技术研究院，北京　100195

Research Institute of Petroleum Exploration & Development, Beijing 100083, China Iraq Regional Company, CNPC, Dubai 500486, UAE Tianjin Boxing Engineering &

针对伊拉克HFY 油田?244.5 mm 套管高压盐膏层封固段长（2 000 m 左右）、孔隙压力高（2.15~2.20 g/cm3）、安全固井窗口窄（0.08 g/cm3）、封固段温度低（30~70 ℃）等特点，以及前期固井中存在的问题开展实验研究，确定了密度为2.28 g/cm3 的抗盐高密度水泥浆最佳盐掺量为10%~15%（BWOW），根据加重剂的特点及紧密堆积可压缩堆积模型、固相需水量的计算及实验评价，确定该密度下加重剂赤铁矿与BCW500S 的合理组成（4∶1）及掺量（80%~83%（BWOC）），引入了抗盐羧酸盐类分散剂， 优化降滤失剂的掺量从10% 降至6%~8%（BWOW），形成的HFY 高密度抗盐水泥浆体系具有浆体稳定性及流变性能好、稠化时间可控、低温下早期抗压强度发展快等特点，结合固井方案的优化，实现了?244.5 mm 套管固井由双级固井简化为单级固井， 且固井质量显著提高。28 口井的成功应用表明该项技术较好地解决了窄密度窗口高压盐膏层的固井难题。

In light of the characteristics of long cementing section(about 2 000 m) of ?244.5 mm casing in high-pressure salt-anhydrate bed in HFY Oilfield of Iraq, high pore pressure (2.15~2.20 g/cm3), narrow safe cementing window (0.08 g/cm3)and low cementing section temperature (30~70 ℃), as well as the problems existing in previous cementing operation, the test and research have been carried out, the optimal salt concentration for salt-tolerant high-density cement slurry of which the density is 2.28 g/cm3 has been determined as 10%~15% (BWOW). In light of the characteristics of weighting and close packing compressible packing model and through calculation and evaluation of solid-phase water demand, the reasonable composition of weighting hematite and BCW500S (4∶1) as well as the concentration (80%~83% (BWOC) ) under such density have been determined. The salt-tolerant carboxylate based dispersant has been introduced, the concentration of filtration loss reducer has been optimized from 10% to 6%~8% (BWOW), and the HFY high-density salt-tolerant cement slurry system so formed has the characteristics such as high slurry stability, good rheological property, controllable thickening time, and quickly-developing early-stage compression strength at low temperature. On the basis of the optimization of cementing program, the cementing of ?244.5 mm casing is simplified from double-stage cementing to single-stage cementing, and the cementing quality is obviously improved. The successful application in 28 wells indicates that, this technology settles the cementing difficulty in high-pressure salt-gypsum bed with narrow-density window.

10.13639/j.odpt.2015.06.010