随钻地层压力测量仪研究新进展

Progress in research and development of measurement-while-drilling apparatuses

随钻地层压力测量仪是保证井下作业安全的重要仪器。为此,调研了国内外典型随钻地层压力测量仪的结构原理以及应用情况,重点介绍了国内2种自主研制产品已取得的重要进展:①西南石油大学和中海石油研究中心共同研制的随钻地层压力测量系统的样机,室内模拟实验表明,该仪器最高耐压70MPa,适用温度0～125℃,工作钻压0～250kN,扭矩0～10kN.m;②中国石油大庆钻探工程公司研制成的SDC-Ⅰ型随钻地层压力测试器,现场测试结果表明:该测试器设计合理,可靠性高,压力测量精度达到0.1%,温度测量精度达到±0.5℃,井下供电功率达到160W,实现了随钻数据上传和井下存储功能,地面可随钻获取井下准确的环空压力、温度、地层压力和地层流度,已初步具备商业化应用的条件。但与国外同类产品相比,国内研制的产品在技术指标上还有一定差距:产品规格少,局限在Φ215.9mm井眼中使用;仅适用最高耐压70 MPa,温度小于125℃的中深井井下环境。最后建议:国内应加大现场试验验证,加强合作交流,以便尽快商业化应用。

The measurement-while-drilling apparatus and method are developed to keep safe downhole operation with the real-time measured formation data. Therefore, an investigation was first made into the basic structure, working principle and application of such representative apparatuses at home and abroad, with a focus on the achieved major progress in two independently developed products in China. The first one is a prototype jointly developed by Southwest Petroleum University and CNOOC Research Center. An indoor simulation experiment was made on the key parts of this prototype apparatus with a tailor-made ground simulator. The experimental data was thus recorded on this prototype apparatus： the allowable highest pressure is 70 MPa; the applicable temperature is in a range of 0 - 125±, working bit weight is 0 - 250 kN; and torque is 0 - 10 kN · m. The second one is SDC-I apparatus, developed by CNPC Daqing Oilfield Drilling Engineering Co. , Ltd. , which has been tested on site for popularization. Pilot tests showed that this apparatus is of reasonable design and high reliability; the precision rate of formation pressure measurement is 0.1% and that of temperature measurement is ±0.5℃ ; and downhole power efficiency is 160 W. With such an apparatus, the measurement-while- drilling data can be uploaded and stored downhole at the same time, thus, such accurate downhole data as annulus pressure, temperature, formation pressure and fluidity can be sent up to ground while drilling. However, compared with the like products aboard, there is still a wide gap in terms of technical qualification of the above independently developed apparatuses. For example, due to their limited sizes, they can be used only in φ215.9 mm borehole wells or in the downhole environment of moderately deep wells with the highest pressure of 70 MPa and the temperature of less than 125℃. In the end, this paper points out that only if more field tests are performed and cooperation with foreign companies is strengthened, should these developed apparatus be verified and quickly put into commercial production and application in China.