鸭深1井钻井液技术

鸭深1井是大庆油田在青海省柴北缘区块布置的第一口重点探井,完钻井深为4950.00m。该井上部地层疏松,承压能力弱,部分井段有破碎带,易发生井漏,狮子沟组至上油砂山组上部地层中,泥岩水化分散性强,易出现缩径、井壁坍塌;下部地层温度和地层压力系数高,抗温和维持井壁稳定是关键。全井存在多层高压盐水层,易发生井漏、井涌、井塌等事故。针对鸭深1井地质特点,通过室内实验研究确定,上部地层采用阳离子聚合物钻井液;钻至下部地层将钻井液转化为阳离子聚磺钻井液,提高钻井液的抗温性和稳定性。现场应用表明,该钻井液体系在高密度条件下具有较强的抑制性、防塌性和较好抗盐抗钙能力;减少了复杂事故的发生,保证了钻井施工的顺利进行。

Drilling Fluid Technology in Well Yashen-1

Well Yashen-1 is the first exploration well in North Chadamu Basin of Qinghai Province. The drilled depth is 4950.00 meters. The shallow formation is loosely compacted and some crushed zones exist in the upper part of the formations penetrated. Mud losses occurs frequently. The upper part of the Shizigou group and the Upper Youshashan group are mainly shale formations characterized by strong hydration and dispersion in contact with water. Wells penetrating these formations always experiences tight hole and hole sloughing. The high temperatures and high pressures in the lower part of the formation make the temperature stability and inhibition of the drilling mud necessary. Moreover, several saltwater zones with high pressures exist along the formation penetrated. A cationic polymer drilling mud was proposed based on laboratory study. Pure cationic polymer mud was used in drilling the shallow holes, and then converted the mud to a cationic polymer sulfonate polymer mud to improve the temperature stability of the mud. As a high density inhibitive mud, this mud had a high salt and calcium tolerance, and it had been successfully used in Daqing Oilfield.