CEM-1型电磁波随钻测量系统的研制与应用

电磁波随钻测量技术是气体、泡沫等非液相钻井的重要测量技术手段。以CEM-1型MWD系统为基础,介绍了系统的构成和工作原理,分析说明了该测量系统的井下发射机系统、非对称偶极子钻杆天线模型、地面接收系统等关键技术,重点分析了低频电磁衰减规律。将该系统在大牛地气田D66-129井进行现场应用,应用结果表明,CEM-1型电磁波随钻测量系统能在钻井液钻井中的循环、起钻和下钻过程中测量和传输数据,并且不受钻井液性质的影响,在电阻率大于4Ω.m的地层传输深度可达3 081 m,工作时间约216 h。系统整体性能能够满足实际工作需要。

The development and application of Model CEM-1 electromagnetic measuring while drilling system

The electromagnetic measuring while drilling (MWD)technology is an important technological means to measurenon-liquid drilling, such as gas and foam drilling. Based on theCEM-1 MWD system, this paper introduces the componentparts and operating principle of the system and makes adetailed analysis of its downhole transmitter system and the keytechnologies, such as asymmetric dipole drillpipe antennamodel and ground receiving system, focusing on the analysis ofthe law for low-frequency electromagnetic attenuation. Thesystem was applied to Well D66-129 in Daniudi Gasfield. Theresult shows that the system can measure and transmit data inthe process of circulation, tripping and running in drilling fluiddrilling and it is free from the effect of the nature of drillingfluid. The transmission depth can reach 3,081 meters in theformations whose resistivity is greater than 4Ω · m and theoperating time is about 216 hours. The whole performance ofthe system can satisfy the requirement of practical operation.