大庆油田雾化／泡沫钻井液的研究与应用

徐深43井是松辽盆地北部勘探项目的一口预探井,井深为3 990 m,目的层为营城组砾岩层、火山岩储层.为提高该井登娄库组及其以下层段的钻井速度,在该井段试验应用了气体钻井技术.在空气钻井过程中遇到地层出水时,即使将空气注入量提高至160 m<'3>/min,井内仍会存在返屑不畅、钻头泥包等问题.因此,通过对发泡剂、稳泡剂、抑制剂进行筛选,研制出了适合大庆油田地层条件的雾化/泡沫钻井液配方,并对其抑制性、抗温性、抗污染能力以及钻井液密度特性进行了评价.该井使用空气钻进14 m后遇地层出水,转为雾化/泡沫,进尺为751 m,钻进目的层395 m,气测全烃最高达到2.9%,稳定基值达到0.5%～0.7%,表明该套雾化/泡沫钻井工艺适合大庆油田地层.

Research and Application of Mist/Foam Drilling Fluid in Daqing Oilfield

Well Xushen43 is an exploration well located in the Songliao Basin, with a completion depth of 3,990 m. The reservoir formations are composed of mainly conglomerate and volcanic rock. Gas drilling was tried in this well to enhance penetration rates of Denglouku Formation and formations below. Air rate was increased to 160 m<'3>/min when formation water was encountered. Even at this high pump rate drilled cut-tings were still not cleaned from the hole effectively, and bit bailing was experienced. By choosing suitable foaming agent, foam stabilizer and inhibitor, a mist/foam mud was developed. Laboratory experiments were done on the inhibitive capacity, temperature stability, contamination tolerance, and mud density re-duction of this mud. Well Xushen43 was drilled to 14 m using air drilling, at which formation water was encountered. The mud was converted to mist/foam mud. Drilling footage using this mist/foam mud was 751 m, with 395 m of which being reservoir formation. Gas logging results showed that the whole hydro-carbon value reached a maximum of 2.9% and a stable base value of 0.5～0.7%. It is suggested that this mist/foam mud is suitable for use Daqing oilfield.