摘要
可循环微泡沫钻井液是由水、固相颗粒(黏土)、表面活性剂(发泡剂)、增黏剂、降滤失剂等制成的一种气、液、固三相分散的胶体体系。室内评价实验结果表明,可循环微泡沫钻井液抗温高达135℃,在NaCl浓度高达10%时仍保持良好的流变性,具有较强的抑制性和良好的防漏失性能。由于其所含的表面活性剂产生泡沫,具有一定的疏水特性,在井内循环过程中,在井壁表面形成稳定的疏水屏障,阻碍自由水向地层的流动,使之不易润湿及渗入裸露的井壁,减少了滤液对泥页岩地层的水化膨胀作用;泡沫钻井液与抑制剂及井壁稳定剂适量添加混合,可有效提高钻井液的防塌效果。室内评价试验确定了可循环微泡沫钻井液使用配方:4%膨润土浆+0.3%Na2CO3+0.5%WP-1+0.3%WDJ-1+0.4%CPS-2000+0.3%FP-1。中原油田4口井和科索1井的现场应用表明,该钻井液可满足中原油田中生界低压、低渗地层和北京中元古界蓟县系雾迷山组海泡石易膨胀、溶解地层、气穴发育地层的欠平衡钻进要求。
Circulative micro-foam drilling fluid is a gas-fluid-liquid dispersoid system made up of water,solid grain（clay）,surfactant（foaming agent）,adhesion promoter,fluid loss additive and so on.Laboratory evaluation result shows that the circulative micro-foam drilling fluid is stable at 135℃ and has good rheological property in 10% salt water.It also has good ability of hole stability and against circulation losing.The surfactant in the drilling fluid has certain hydrophobic property for the foam.During the process of cycle in well,hydrophobic barrier is formed at the surface of borehole,which stops the flow of free water to the formation,and hydrate expansion action of filtrate to mud shale formations is weakened.When inhibitor and stabilizer for borehole wall are added into the drilling fluid,the anti-caving effect of the drilling fluid will become better.The formula of the circulative micro-foam drilling fluid is fixed through laboratory evaluation experiment：4% bentonite mud＋0.3% Na2CO3＋0.5%WP-1＋0.3%WDJ-1＋0.4%CPS-2000＋0.3%FP-1.It is applied in four wells of Zhongyuan oilfield and Kesuo-1 well.The results present that this drilling fluid can meet the demands of under balanced drilling in Mesozoic low-pressure and low-permeability formations in Zhongyuan oilfield and sepiolite,dissolved cavitating formations in Wumishan formation,Jixian system,mid-Proterozoic in Beijing.
出处
《中外能源》
CAS
2010年第7期57-59,共3页
Sino-Global Energy
关键词
可循环微泡沫钻井液
欠平衡钻井
表面活性剂
防漏
circulative micro-foam drilling fluid
underbalanced drilling
surfactant
leak protection
