CN102650208B - Nuclear magnetic resonance logger probe while drilling and nuclear magnetic resonance logger while drilling - Google Patents
Nuclear magnetic resonance logger probe while drilling and nuclear magnetic resonance logger while drilling Download PDFInfo
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Abstract
本发明提供一种随钻核磁共振测井仪探头及随钻核磁共振测井仪。该随钻核磁共振测井仪包括:探头骨架,探头骨架的中心穿设有泥浆管;在探头骨架内、且在泥浆管上套设有圆环状的第一主磁体和第二主磁体,第一主磁体和第二主磁体均为轴向充磁,且第一主磁体和第二主磁体极性相同的一端相对设置;在探头骨架的外围侧壁上的中间位置固定嵌设有用于形成脉冲磁场的天线;在第一主磁体和第二主磁体之间、且在泥浆管上同轴套设有至少一对的圆环状的聚焦磁体,构成所述每对聚焦磁体中的两个聚焦磁体关于所述天线的中截面对称,聚焦磁体为径向充磁。本发明的随钻核磁共振测井仪探头,可增加敏感区域在垂向的延伸长度,提高测量的信噪比及测量结果的精度。
The invention provides a probe of a nuclear magnetic resonance logging tool while drilling and a nuclear magnetic resonance logging tool while drilling. The NMR logging while drilling instrument includes: a probe skeleton, a mud pipe is pierced through the center of the probe skeleton; a ring-shaped first main magnet and a second main magnet are sleeved in the probe skeleton and on the mud pipe, Both the first main magnet and the second main magnet are axially magnetized, and one end with the same polarity of the first main magnet and the second main magnet is arranged oppositely; An antenna forming a pulsed magnetic field; between the first main magnet and the second main magnet, and coaxially sleeved on the mud pipe, at least one pair of ring-shaped focusing magnets constitute two of the said pair of focusing magnets. A focusing magnet is symmetrical about the middle section of the antenna, and the focusing magnet is radially magnetized. The probe of the nuclear magnetic resonance logging tool while drilling of the present invention can increase the vertical extension length of the sensitive area, improve the signal-to-noise ratio of the measurement and the accuracy of the measurement result.
Description
技术领域technical field
本发明涉及核磁共振测井技术,尤其涉及一种随钻核磁共振测井仪探头及随钻核磁共振测井仪。The invention relates to nuclear magnetic resonance logging technology, in particular to a probe of a nuclear magnetic resonance logging tool while drilling and a nuclear magnetic resonance logging tool while drilling.
背景技术Background technique
随钻核磁共振测井仪是利用核磁共振原理测量油井周围的地层情况,从而探测地层中与油气特征相关的信息,其主要通过探头形成磁场并采集共振信号,进而根据共振信号对赋存在地层岩石孔隙中的流体进行分析,以直接测量储层流体中氢核的密度,并可将利用核磁共振信号获得的核磁数据直接转换为视含水孔隙度,还可以确定储层中不同流体的存在、含量及流体的相关特性。The logging-while-drilling nuclear magnetic resonance tool uses the principle of nuclear magnetic resonance to measure the formation conditions around the oil well, so as to detect the information related to the oil and gas characteristics in the formation. It mainly forms a magnetic field through the probe and collects the resonance signal, and then according to the resonance signal. The fluid in the pores can be analyzed to directly measure the density of hydrogen nuclei in the reservoir fluid, and the nuclear magnetic data obtained by using nuclear magnetic resonance signals can be directly converted into apparent water-bearing porosity, and the existence and content of different fluids in the reservoir can also be determined and fluid properties.
其中,探头是在油气井下激发核磁共振现象和接收核磁共振信号的关键部件,探头的结构设计决定了测井仪的测量方式、产生核磁共振的共振区域及核磁共振信号强度等关键性能。探头主要包括磁体和天线,磁体用于在井眼周围的地层中产生静磁场,以对地层中的液态油气水中的氢原子进行激发;天线用于向地层发射射频脉冲以形成脉冲磁场,通过该脉冲磁场激发地层中已经被所述静磁场极化的氢原子产生核磁共振现象,同时还用于接收和采集地层的氢原子产生的核磁共振信号。Among them, the probe is the key component to excite the nuclear magnetic resonance phenomenon and receive the nuclear magnetic resonance signal under the oil and gas well. The structural design of the probe determines the key performance such as the measurement method of the logging tool, the resonance area where the nuclear magnetic resonance is generated, and the signal strength of the nuclear magnetic resonance. The probe mainly includes a magnet and an antenna. The magnet is used to generate a static magnetic field in the formation around the wellbore to excite the hydrogen atoms in the liquid oil, gas and water in the formation; the antenna is used to transmit radio frequency pulses to the formation to form a pulsed magnetic field. The pulsed magnetic field excites hydrogen atoms in the formation that have been polarized by the static magnetic field to generate nuclear magnetic resonance phenomena, and is also used to receive and collect nuclear magnetic resonance signals generated by hydrogen atoms in the formation.
图1为现有技术中的随钻核磁共振测井仪探头的结构示意图,如图1所示,该探头主要包括:上下相对设置的两个主磁体11,设置在两个主磁体11之间的天线12,以及用于容置并固定主磁体11和天线12的探头骨架;其中,主磁体11呈圆环状,且两主磁体11的同极相对。这种结构下,主磁体11形成的静磁场B0的方向和天线发射射频脉冲所形成的脉冲磁场B1的方向在探头中间位置的横截面上互相垂直(B0垂直于B1核磁共振的必要激发条件之一),即,在地层对应该位置处形成环形的、可产生核磁共振的敏感区域M。Fig. 1 is the structure schematic diagram of the probe of the nuclear magnetic resonance logging instrument while drilling in the prior art, as shown in Fig. 1, this probe mainly comprises: two main magnets 11 that are arranged up and down oppositely, are arranged between two main magnets 11 The antenna 12, and the probe frame for accommodating and fixing the main magnet 11 and the antenna 12; wherein, the main magnet 11 is in the shape of a ring, and the same poles of the two main magnets 11 face each other. Under this structure, the direction of the static magnetic field B0 formed by the main magnet 11 and the direction of the pulsed magnetic field B1 formed by the radio frequency pulse emitted by the antenna are perpendicular to each other on the cross section of the middle position of the probe ( B0 is perpendicular to B1 of the nuclear magnetic resonance One of the necessary excitation conditions), that is, a ring-shaped sensitive region M that can generate nuclear magnetic resonance is formed at the position corresponding to the formation.
现有技术的这种探头的静磁场强度较低,其产生核磁共振的共振频率也较低,从而导致信号强度不够高,另外,由于主磁体和天线的设置方式使得敏感区域M在垂向上的高度较小,一般为:20~25.5mm,而在测量过程中每组信号的采集需要经历一个3~5秒的测量周期,而同时探头是持续钻进的,从而使在这个测量周期内,敏感区域M的位置切换过于频繁,导致了测量结果的信噪比较低(研究表明,信噪比与敏感区域高度成正比),影响测量精度。The static magnetic field strength of this probe in the prior art is low, and the resonance frequency of nuclear magnetic resonance is also low, resulting in insufficient signal strength. In addition, due to the arrangement of the main magnet and the antenna, the sensitive area M is vertically The height is small, generally: 20-25.5mm, and the acquisition of each group of signals needs to go through a measurement period of 3-5 seconds during the measurement process, and at the same time the probe is continuously drilling, so that in this measurement period, The location of the sensitive area M is switched too frequently, resulting in a low signal-to-noise ratio of the measurement results (research shows that the signal-to-noise ratio is proportional to the height of the sensitive area), which affects the measurement accuracy.
发明内容Contents of the invention
针对现有技术中的上述缺陷,本发明提供一种用于探测地层岩石和流体信息的随钻核磁共振测井仪探头及随钻核磁共振测井仪,达到了提高可产生核磁共振的敏感区域的高度,提高信噪比,从而提高测量精度的目的。Aiming at the above-mentioned defects in the prior art, the present invention provides a probe of a nuclear magnetic resonance logging tool while drilling and a nuclear magnetic resonance logging tool while drilling for detecting formation rock and fluid information, which improves the sensitive area that can generate nuclear magnetic resonance The height, improve the signal-to-noise ratio, thereby improving the purpose of measurement accuracy.
本发明提供一种随钻核磁共振测井仪探头,包括:柱状的探头骨架,所述探头骨架的中心轴处穿设有供钻井液流通的泥浆管;在所述探头骨架内、且在所述泥浆管上同轴套设有圆环状的第一主磁体和第二主磁体,所述第一主磁体和第二主磁体均为轴向充磁,且所述第一主磁体和所述第二主磁体极性相同的一端相对设置;在所述探头骨架的外围侧壁上、且对应所述第一主磁体和第二主磁体的中间位置固定嵌设有用于形成脉冲磁场的天线;在所述第一主磁体和第二主磁体之间、且在所述泥浆管上同轴套设有至少一对的圆环状的聚焦磁体,构成所述每对聚焦磁体中的两个聚焦磁体关于所述天线的中截面对称,所述聚焦磁体为径向充磁,且所述聚焦磁体与所述探头骨架相对固定设置。The present invention provides a probe of a nuclear magnetic resonance logging tool while drilling, comprising: a columnar probe frame, the central axis of the probe frame is pierced with a mud pipe for the circulation of drilling fluid; The coaxial sleeve on the mud pipe is provided with a ring-shaped first main magnet and a second main magnet, and the first main magnet and the second main magnet are both axially magnetized, and the first main magnet and the second main magnet are One end with the same polarity of the second main magnet is oppositely arranged; on the peripheral side wall of the probe frame and corresponding to the middle position of the first main magnet and the second main magnet, an antenna for forming a pulsed magnetic field is fixedly embedded ; Between the first main magnet and the second main magnet, and on the mud pipe, at least one pair of ring-shaped focusing magnets are coaxially sleeved, forming two of each pair of focusing magnets The focusing magnet is symmetrical with respect to the middle section of the antenna, the focusing magnet is radially magnetized, and the focusing magnet is relatively fixed to the probe frame.
本发明还提供一种随钻核磁共振测井仪,包括:井下钻具及井上信号处理设备,所述井下钻具的钻铤中固定设置有如上所述的随钻核磁共振测井仪探头。The present invention also provides a logging-while-drilling nuclear magnetic resonance tool, comprising: a downhole drilling tool and an uphole signal processing device, wherein the probe of the nuclear magnetic resonance logging-while-drilling tool as described above is fixedly arranged in the drill collar of the downhole drilling tool.
本发明提供的随钻核磁共振测井仪探头静磁场分布,可使能够产生核磁共振的敏感区域在垂向的延伸长度得到显著增加,当钻头钻进时,在保证探头的自转不会影响测量的同时;还能使得在采集每组信号的测量周期内,敏感区域的位置切换次数下降,提高了测量的信噪比及测量结果的精度。The probe static magnetic field distribution of the NMR logging tool while drilling provided by the present invention can significantly increase the vertical extension length of the sensitive area capable of generating nuclear magnetic resonance, and when the drill bit is drilling, the rotation of the probe will not affect the measurement At the same time; it can also reduce the number of position switching in the sensitive area during the measurement period of collecting each group of signals, and improve the signal-to-noise ratio of the measurement and the accuracy of the measurement results.
附图说明Description of drawings
图1为现有技术中的随钻核磁共振测井仪探头的结构示意图;Fig. 1 is the structural representation of the probe of the NMR logging tool while drilling in the prior art;
图2为本发明随钻核磁共振测井仪探头实施例的结构示意图;Fig. 2 is the structural representation of the probe embodiment of the nuclear magnetic resonance logging instrument while drilling of the present invention;
图3为图1中第一主磁体或第二主磁体一实施例的结构示意图;Fig. 3 is a schematic structural view of an embodiment of the first main magnet or the second main magnet in Fig. 1;
图4为图1中第一主磁体或第二主磁体另一实施例的结构示意图;Fig. 4 is a structural schematic diagram of another embodiment of the first main magnet or the second main magnet in Fig. 1;
图5为图1中第一主磁体或第二主磁体又一实施例的结构示意图;Fig. 5 is a structural schematic diagram of another embodiment of the first main magnet or the second main magnet in Fig. 1;
图6为图1中聚焦磁体实施例的结构示意图;Fig. 6 is a schematic structural view of an embodiment of the focusing magnet in Fig. 1;
图7为本发明探头所形成的磁场强度分布示意图;Fig. 7 is the schematic diagram of the magnetic field strength distribution that the probe of the present invention forms;
图8为图1中天线的结构示意图。FIG. 8 is a schematic structural diagram of the antenna in FIG. 1 .
具体实施方式Detailed ways
随钻核磁共振测井仪可以用于垂直井、倾斜井,甚至水平井中,因此,随钻式核磁共振测井仪的钻进方向为探头骨架的中心轴的延伸方向,即“轴向”,但并不一定为垂向;但为说明方便,在实施例中,将以用于垂直井为例进行阐述,也就是说,在下述实施例中“轴向”即指垂向。但是,本实施例的内容并不是对本发明的限定。The while-drilling nuclear magnetic resonance logging tool can be used in vertical wells, inclined wells, and even horizontal wells. Therefore, the drilling direction of the while-drilling nuclear magnetic resonance logging tool is the extension direction of the central axis of the probe frame, that is, "axial". But it is not necessarily vertical; but for the convenience of description, in the embodiments, it will be described by taking a vertical well as an example, that is to say, "axial" in the following embodiments refers to the vertical direction. However, the content of this embodiment does not limit the present invention.
本实施例提供一种随钻核磁共振测井仪探头,如图2所示,包括:沿垂向延伸的、柱状的探头骨架10,探头骨架10的中心轴处穿设有供钻井液流通的泥浆管101;在探头骨架10内、且在泥浆管101上同轴套设有圆环状的、尺寸相同的第一主磁体21和第二主磁体22,第一主磁体21和第二主磁体22均为轴向充磁,且第一主磁体21和所述第二主磁体22极性相同的一端相对设置;在探头骨架10的外围侧壁上、且对应第一主磁体21和第二主磁体22的中间位置固定嵌设有用于形成脉冲磁场的天线24;在第一主磁体21和第二主磁体22之间、且在泥浆管101上同轴套设有至少一对的圆环状的聚焦磁体23,构成每对聚焦磁体中的两个聚焦磁体23关于天线24的中截面对称,聚焦磁体23为径向充磁,且聚焦磁体23与探头骨架10相对固定设置。This embodiment provides a probe of a nuclear magnetic resonance logging tool while drilling, as shown in Figure 2, comprising: a vertically extending, columnar probe frame 10, the central axis of the probe frame 10 is pierced with a hole for the circulation of drilling fluid Mud pipe 101; in the probe frame 10 and coaxially sleeved on the mud pipe 101, a ring-shaped first main magnet 21 and a second main magnet 22 of the same size are arranged, and the first main magnet 21 and the second main magnet The magnets 22 are all axially magnetized, and one end of the first main magnet 21 and the second main magnet 22 with the same polarity are oppositely arranged; on the peripheral side wall of the probe frame 10, and corresponding to the first main magnet 21 and the second main magnet The middle position of the two main magnets 22 is fixedly embedded with an antenna 24 for forming a pulsed magnetic field; between the first main magnet 21 and the second main magnet 22, and coaxially sleeved on the mud pipe 101, at least a pair of circular The ring-shaped focusing magnet 23 constitutes two focusing magnets 23 in each pair of focusing magnets, which are symmetrical to the middle section of the antenna 24 .
具体地,圆柱状的探头骨架10的中心轴处可设有通孔,可将一该通孔内固定嵌设一圆管状的、上下延伸的泥浆管101,可选地,也可将该通孔可直接作为泥浆管101;第一主磁体21、第二主磁体22及聚焦磁体23可以固定套设在泥浆管101的周围,此时,探头骨架10内用于容置第一主磁体21、第二主磁体22及聚焦磁体23的容置腔可以大于上述各部件的体积;但当泥浆管101为探头骨架10上的一通孔时,可以将第一主磁体21、第二主磁体22及聚焦磁体23分别固定嵌设在特定的位置,此时,用于容置这些部件的容置腔应与各部件的体积相匹配,以保证在钻进过程中,第一主磁体21、第二主磁体22及聚焦磁体23的相对位置固定不变。Specifically, a through hole may be provided at the central axis of the cylindrical probe frame 10, and a circular tubular mud pipe 101 extending up and down may be fixedly embedded in the through hole. Optionally, the through hole may also be The hole can be directly used as the mud pipe 101; the first main magnet 21, the second main magnet 22 and the focusing magnet 23 can be fixedly sleeved around the mud pipe 101. At this time, the probe frame 10 is used to house the first main magnet 21 , The accommodating cavity of the second main magnet 22 and the focusing magnet 23 can be greater than the volume of the above-mentioned parts; but when the mud pipe 101 is a through hole on the probe frame 10, the first main magnet 21, the second main magnet 22 can be and focusing magnets 23 are respectively fixedly embedded in specific positions. At this time, the accommodating cavity for accommodating these parts should match the volume of each part, so as to ensure that the first main magnet 21, the second The relative positions of the two main magnets 22 and the focusing magnet 23 are fixed.
天线24围绕在聚焦磁体的周围,且每对聚焦磁体中的两个聚焦磁体23、以及第一主磁体和第二主磁体均关于天线24的水平中截面对称。第一主磁体21和第二主磁体22均为轴向充磁,即,第一主磁体21和第二主磁体22的两端分别为N极和S极;聚焦磁体23为径向充磁,即,聚焦磁体23的内环面可以为N极或S极、外环面可以为S极或N极;且当第一主磁体21的N极和第二主磁体22的N极相对设置时,聚焦磁体23的内环面为S极,外环面为N极;当第一主磁体21的S极和第二主磁体22的S极相对设置时,当第一主磁体21的S极和第二主磁体22的S极相对设置时,聚焦磁体23的内环面为N极,外环面为S极;第一主磁体21与第二主磁体22形成的静磁场强度可以相同。The antenna 24 surrounds the focusing magnets, and the two focusing magnets 23 in each pair of focusing magnets, as well as the first main magnet and the second main magnet are symmetrical about the horizontal mid-section of the antenna 24 . The first main magnet 21 and the second main magnet 22 are axially magnetized, that is, the two ends of the first main magnet 21 and the second main magnet 22 are N poles and S poles respectively; the focusing magnet 23 is radially magnetized , that is, the inner annulus of the focusing magnet 23 can be N pole or S pole, and the outer annulus can be S pole or N pole; and when the N pole of the first main magnet 21 and the N pole of the second main magnet 22 are arranged oppositely , the inner annulus of the focusing magnet 23 is an S pole, and the outer annulus is an N pole; when the S pole of the first main magnet 21 and the S pole of the second main magnet 22 are arranged oppositely, when the S When the pole and the S pole of the second main magnet 22 are arranged oppositely, the inner annulus of the focusing magnet 23 is an N pole, and the outer annulus is an S pole; the static magnetic field intensity formed by the first main magnet 21 and the second main magnet 22 can be the same .
优选地,聚焦磁体可以为多对,例如两对,靠近天线24的水平中截面的一对聚焦磁体23之间的距离可以为2~5mm;靠近第一主磁体21的聚焦磁体23和靠近第二主磁极22的聚焦磁体23的垂向高度可以为靠近天线24的水平中截面的一对聚焦磁体23的1/4~1/2;且聚焦磁体23的直径也可以小于或等于第一主磁体21或第二主磁体22的直径,以进一步方便天线24布置。Preferably, the focusing magnets can be many pairs, such as two pairs, and the distance between a pair of focusing magnets 23 close to the horizontal middle section of the antenna 24 can be 2-5mm; The vertical height of the focus magnet 23 of two main magnetic poles 22 can be 1/4~1/2 of a pair of focus magnet 23 near the horizontal middle section of antenna 24; And the diameter of focus magnet 23 also can be less than or equal to the first main magnet The diameter of the magnet 21 or the second main magnet 22 is to further facilitate the arrangement of the antenna 24 .
本实施例的随钻核磁共振测井仪探头的中第一主磁体21、第二主磁体22聚焦磁体23的设置,产生的静磁场的磁感应强度分布如图7所示,探头的外侧面Y与垂直井的井壁J形成一间隙,探头Y的中心轴N同时代表了泥浆管101的延伸方向。由图7可以看出,对应探头垂向中间处,磁感应强度沿垂向延伸且均匀分布,从而使得可形成核磁共振的敏感区域M在垂向的延伸长度得到显著增加(如图2所示),具体地,本实施例的敏感区域M沿钻进方向的长度可以达到100~150mm,大约为现有技术中的敏感区域长度的5倍以上;另外,多对聚焦磁体23的设置还可以提高静磁场强度,从而提高了所采集到的核磁共振信号的强度。The arrangement of the first main magnet 21 and the second main magnet 22 focusing magnet 23 in the MWD NMR logging tool probe of the present embodiment, the magnetic induction intensity distribution of the static magnetic field generated is as shown in Figure 7, the outer surface Y of the probe A gap is formed with the well wall J of the vertical well, and the central axis N of the probe Y represents the extension direction of the mud pipe 101 at the same time. It can be seen from Figure 7 that, corresponding to the vertical middle of the probe, the magnetic induction intensity extends vertically and is evenly distributed, so that the vertical extension length of the sensitive area M that can form nuclear magnetic resonance is significantly increased (as shown in Figure 2) , specifically, the length of the sensitive region M of the present embodiment along the drilling direction can reach 100-150 mm, which is about 5 times the length of the sensitive region in the prior art; in addition, the arrangement of multiple pairs of focusing magnets 23 can also improve the The intensity of the static magnetic field is increased, thereby increasing the intensity of the acquired nuclear magnetic resonance signal.
另外,由于第一主磁体21和第二主磁体22之间设置了至少一对的聚焦磁体23,因此,所形成的静磁场的强度也得到提高。由于,共振频率可通过下式确定:In addition, since at least one pair of focusing magnets 23 is disposed between the first main magnet 21 and the second main magnet 22, the strength of the formed static magnetic field is also increased. Since, the resonant frequency can be determined by:
其中,γ为旋磁比,对于氢核f0为产生核磁共振的共振频率;B0为静磁场的强度。Among them, γ is the gyromagnetic ratio, for the hydrogen nucleus f 0 is the resonant frequency that produces nuclear magnetic resonance; B 0 is the strength of the static magnetic field.
可见,在敏感区域体积不变情况下,共振频率正比于静磁场的强度B0,因此,本实施例提供的随钻核磁共振测井仪探头具有较高的共振频率,且测量的信噪比通常与共振频率的3/2次方成正比,进而,进一步提高了测量的信噪比,有利于获得更好的测量精度。It can be seen that when the volume of the sensitive area is constant, the resonance frequency is proportional to the strength B 0 of the static magnetic field. Therefore, the probe of the NMR logging tool provided in this embodiment has a relatively high resonance frequency, and the signal-to-noise ratio of the measurement is generally It is proportional to the 3/2 power of the resonance frequency, and further improves the signal-to-noise ratio of the measurement, which is beneficial to obtain better measurement accuracy.
在进行垂直井的核磁共振测量时,可将本实施例的随钻核磁共振测井仪探头可固定设置在钻头上方(钻头背离钻进方向的一侧)的钻铤内,或者固定设置在钻铤与钻头之间,以作为钻铤的一部分。由于本实施例提供的探头所形成的可形成核磁共振的敏感区域M呈与钻头中心轴同轴的圆柱状,因此,当钻头垂直向下钻进时,探头随钻头的自转不会影响测量;而同时由于敏感区域M在钻进方向上长度的增加,使得在采集每组信号的测量周期内,敏感区域M的位置切换次数也显著减少,也就是说,由于敏感区域M的长度增加了五倍,使得一个测量周期内钻头在垂向的位移不会超过敏感区域M,从而便可避免现有技术中,天线发射射频信号后等待回波信号的时间段内,天线24已经完全移出发射设备信号时敏感区域M所处的位置,而此时所处的敏感区域M的位置处,由于停留时间尚未达到对地层极化所需的极化时间,从而导致最终采集到信号不准确的情况;本实施例通过增加敏感区域M在钻进方向上的长度,提高了测量的信噪比(在核磁共振测量中已证实信噪比正比于敏感区域在钻进方向上的长度),提高了最终测量结果的精度。When performing nuclear magnetic resonance measurements of vertical wells, the probe of the NMR logging tool while drilling in this embodiment can be fixedly installed in the drill collar above the drill bit (the side of the drill bit away from the drilling direction), or fixedly installed in the drill collar. Between the collar and the drill bit as part of the drill collar. Since the sensitive area M formed by the probe provided in this embodiment can form nuclear magnetic resonance is a cylindrical shape coaxial with the central axis of the drill bit, therefore, when the drill bit drills vertically downward, the rotation of the probe with the drill bit will not affect the measurement; At the same time, due to the increase in the length of the sensitive area M in the drilling direction, the position switching times of the sensitive area M are also significantly reduced during the measurement period of collecting each group of signals, that is to say, because the length of the sensitive area M increases by five times, so that the vertical displacement of the drill bit in one measurement cycle will not exceed the sensitive area M, thereby avoiding the prior art, the antenna 24 has completely moved out of the transmitting device during the period of waiting for the echo signal after the antenna transmits the radio frequency signal The position of the sensitive area M at the time of the signal, and at the position of the sensitive area M at this time, because the residence time has not yet reached the polarization time required for the polarization of the formation, the final signal is inaccurate; This embodiment improves the signal-to-noise ratio of the measurement by increasing the length of the sensitive area M in the drilling direction (it has been confirmed that the signal-to-noise ratio is proportional to the length of the sensitive area in the drilling direction in the nuclear magnetic resonance measurement), and improves the final The precision of the measurement results.
优选地,如图2所示,聚焦磁体23可以为两对,构成两对聚焦磁体的四个聚焦磁体沿垂向等间隔排列,且位于最顶端的聚焦磁体的顶面和位于最底端的聚焦磁体的底面分布伸出天线的两端。Preferably, as shown in Figure 2, the focus magnets 23 can be two pairs, and the four focus magnets that constitute two pairs of focus magnets are arranged at equal intervals in the vertical direction, and the top surface of the focus magnet at the top and the focus magnet at the bottom The bottom surface of the magnet protrudes from both ends of the antenna.
在上述实施例中,如图8所示,天线24为被绕制成圆柱螺旋线状的一根导线,该柱状的螺旋线的中心轴与第一主磁体21、第二主磁体22及聚焦磁体23的中心轴在同一直线上,以适应自身的旋转运动;优选地,天线24可由一根铜线或铜带绕制而成,天线24的第一引出端241和第二引出端242可连接至一LRC谐振电路(图未示),以通过调节该LRC谐振电路中的电容使天线24的谐振频率与敏感区域M处的地层中的氢核的共振频率相同,从而才能激发核磁共振现象。In the above-described embodiment, as shown in FIG. 8 , the antenna 24 is a wire wound into a cylindrical helix, and the central axis of the columnar helix is connected to the first main magnet 21, the second main magnet 22 and the focus. The central axis of the magnet 23 is on the same straight line, so as to adapt to the rotational movement of itself; Connect to an LRC resonant circuit (not shown), so that the resonant frequency of the antenna 24 is the same as the resonant frequency of the hydrogen nuclei in the formation at the sensitive area M by adjusting the capacitance in the LRC resonant circuit, so as to excite the nuclear magnetic resonance phenomenon .
本实施例的随钻核磁共振测井仪探头可形成核磁共振的敏感区域M沿径向上的厚度可以达到15~20mm,可以有效消除钻头引起探头的径向振动对测量精度的不利影响。The probe of the NMR logging tool in this embodiment can form the NMR sensitive region M with a radial thickness of 15-20mm, which can effectively eliminate the adverse effects of the radial vibration of the probe caused by the drill bit on the measurement accuracy.
进一步地,上述天线24可采用柔性电路板(Flexible Printed Circuit Board,FPCB)蚀刻技术制造。Further, the above-mentioned antenna 24 can be manufactured by using a flexible printed circuit board (Flexible Printed Circuit Board, FPCB) etching technology.
在上述实施例中,如图2和图8所示,构成天线24的中间部分的圆柱螺旋线的导程大于构成天线24两端处的圆柱螺旋线的导程;即,在天线24的中间部分,相邻的两线圈之间的距离较小,线圈绕制得较密集,在天线24的两端处,相邻的两线圈之间距离较大,线圈绕制得较稀疏。本实施例中对天线的多个线圈的间距的优化,可以使天线产生的射频磁场在垂向上具有更好的均匀性,且不会对射频磁场在天线径向上的分布造成不利影响;从而进一步保证了与第一主磁体21、第二主磁体22和聚焦磁体23共同形成的静磁场相匹配,以将地层处于敏感区域M内的氢核完全激发。In the above-described embodiment, as shown in FIGS. 2 and 8 , the lead of the cylindrical helix constituting the middle portion of the antenna 24 is larger than the lead of the cylindrical helix constituting the two ends of the antenna 24; that is, in the middle of the antenna 24 Partly, the distance between two adjacent coils is relatively small, and the coils are wound densely. At both ends of the antenna 24 , the distance between two adjacent coils is relatively large, and the coils are wound relatively sparsely. In this embodiment, the optimization of the spacing of multiple coils of the antenna can make the radio frequency magnetic field generated by the antenna have better uniformity in the vertical direction, and will not adversely affect the distribution of the radio frequency magnetic field in the radial direction of the antenna; thus further It is ensured that the static magnetic field jointly formed by the first main magnet 21 , the second main magnet 22 and the focusing magnet 23 matches, so as to fully excite the hydrogen nuclei in the sensitive region M of the formation.
更具体地,在上述实施例中,请参照图2至6,第一主磁体由至少三块磁体块依次拼接而成;和/或第二主磁体22由至少三块磁体块依次拼接而成;和/或聚焦磁体23由至少三块磁体块依次拼接而成。即每个磁体可以为一体结构或多个小块磁体拼接而成的结构;例如,第一主磁体21或第二主磁体22可以采用多个圆环状的分磁体212叠放固定在一起的结构(如图3所示),或者第一主磁体21或第二主磁体22也可以采用由多个水平截面为梯形的分磁体231拼接而成的环状结构(如图4所示),当然,第一主磁体21或第二主磁体22也可以采用一体结构(如图5所示);聚焦磁体23可以采用由多个水平截面为扇形的分磁体231拼接而成的环状结构(如图6所示),当然也可以采用一体结构或如图4中第一主磁体21或第二主磁体22的结构。More specifically, in the above-mentioned embodiment, please refer to FIGS. 2 to 6, the first main magnet is formed by sequentially splicing at least three magnet blocks; and/or the second main magnet 22 is formed by sequentially splicing at least three magnet blocks ; and/or the focusing magnet 23 is spliced sequentially by at least three magnet blocks. That is, each magnet can be an integral structure or a structure spliced by multiple small magnets; for example, the first main magnet 21 or the second main magnet 22 can be stacked and fixed together by a plurality of ring-shaped sub-magnets 212 structure (as shown in Figure 3), or the first main magnet 21 or the second main magnet 22 can also adopt a ring structure (as shown in Figure 4 ) spliced by a plurality of sub-magnets 231 whose horizontal section is trapezoidal, Certainly, the first main magnet 21 or the second main magnet 22 can also adopt an integral structure (as shown in Figure 5); the focusing magnet 23 can adopt the annular structure ( As shown in FIG. 6 ), of course, an integral structure or the structure of the first main magnet 21 or the second main magnet 22 in FIG. 4 may also be adopted.
本发明另一实施例提供一种随钻核磁共振测井仪,包括:井下钻具及井上信号处理设备,井下钻具的钻铤中固定设置有如上任一实施例所述的随钻核磁共振测井仪探头,该随钻核磁共振测井仪探头的具体结构及工作原理与上述各实施例类似,在此不再赘述。Another embodiment of the present invention provides a nuclear magnetic resonance logging tool while drilling, including: a downhole drilling tool and an uphole signal processing device. As for the well tool probe, the specific structure and working principle of the LWD NMR logging tool probe are similar to those of the above-mentioned embodiments, and will not be repeated here.
本实施例提供的随钻核磁共振测井仪,其探头形成静磁场,可使能够产生核磁共振的敏感区域在垂向的延伸长度得到显著增加,当钻头钻进时,在保证探头的自转不会影响测量的同时;还能使得在采集每组信号的测量周期内,敏感区域的位置切换次数下降,提高了测量的信噪比及测量结果的精度。In the NMR logging tool while drilling provided in this embodiment, the probe forms a static magnetic field, which can significantly increase the vertical extension of the sensitive area that can generate NMR. When the drill bit is drilling, the rotation of the probe is guaranteed. While affecting the measurement, it can also reduce the number of position switching in the sensitive area during the measurement cycle of collecting each group of signals, and improve the signal-to-noise ratio of the measurement and the accuracy of the measurement results.
最后应说明的是:以上各实施例仅用以说明本发明的技术方案,而非对其限制;尽管参照前述各实施例对本发明进行了详细的说明,本领域的普通技术人员应当理解:其依然可以对前述各实施例所记载的技术方案进行修改,或者对其中部分或者全部技术特征进行等同替换;而这些修改或者替换,并不使相应技术方案的本质脱离本发明各实施例技术方案的范围。Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.
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Families Citing this family (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10309215B2 (en) * | 2014-05-01 | 2019-06-04 | Halliburton Energy Services, Inc. | Casing segment having at least one transmission crossover arrangement |
AR103439A1 (en) * | 2015-03-05 | 2017-05-10 | Halliburton Energy Services Inc | NUCLEAR MAGNETIC RESONANCE SYSTEMS, SYSTEMS AND METHODS |
CN104765072B (en) * | 2015-03-25 | 2017-11-24 | 吉林大学 | A kind of method for carrying out magnetic resonance forward probe with loop aerial rotation |
CN105114070B (en) * | 2015-09-23 | 2018-04-10 | 中国石油大学(北京) | Three-dimensional NMR logging instrument probe, logging instrument and antenna excitation method |
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CN105201498B (en) * | 2015-09-23 | 2018-03-09 | 中国石油大学(北京) | Nuclear magnetic resonance downhole fluid analysis instrument |
CN107035367A (en) * | 2017-04-28 | 2017-08-11 | 北京捷威思特科技有限公司 | NMR while drilling instrument magnet |
CN108565087B (en) * | 2018-03-05 | 2021-01-01 | 中国石油天然气股份有限公司 | Nuclear magnetic resonance logging instrument and nuclear magnetic resonance permanent magnet thereof |
CN108505986A (en) * | 2018-03-09 | 2018-09-07 | 中国石油天然气股份有限公司 | Nuclear magnetic resonance downhole fluid identification device and downhole fluid identification probe thereof |
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CN108533257A (en) * | 2018-06-08 | 2018-09-14 | 北京捷威思特科技有限公司 | NMR logging instrument magnet |
CN109236283A (en) * | 2018-09-05 | 2019-01-18 | 中国石油大学(北京) | NMR logging instrument probe and NMR logging instrument |
CN109782362B (en) * | 2018-12-13 | 2020-08-11 | 中国石油大学(北京) | Downhole nuclear magnetic resonance while drilling instrument magnet, probe and nuclear magnetic resonance while drilling instrument |
CN110058320A (en) * | 2019-04-28 | 2019-07-26 | 吉林大学 | A kind of adjustable active field nuclear magnetic resonance log probe of detecting area and its detection method |
CN110761782B (en) * | 2019-11-13 | 2024-02-09 | 中国石油天然气集团有限公司 | Direction while-drilling nuclear magnetic resonance logging device for geosteering |
CN111810134B (en) * | 2019-12-26 | 2024-03-26 | 北京默凯斯威能源技术有限公司 | Probe magnet device of petroleum nuclear magnetic resonance logging instrument |
CN113161101B (en) * | 2020-01-20 | 2023-11-28 | 中国石油天然气股份有限公司 | Permanent magnet for nuclear magnetic resonance logging instrument |
CN115045651A (en) * | 2021-03-09 | 2022-09-13 | 中国石油天然气股份有限公司 | NMR logging tool antenna and probe for measuring against the borehole wall |
CN113216948B (en) * | 2021-05-19 | 2023-03-24 | 中国石油大学(北京) | Multi-coil-structure while-drilling nuclear magnetic resonance logging device and method |
CN114412448B (en) * | 2022-01-20 | 2025-02-18 | 中国矿业大学 | A nuclear magnetic resonance-based coal reservoir structure testing while-drilling probe and testing method |
CN115467658B (en) * | 2022-08-18 | 2025-01-03 | 燕山大学 | Probe structure of nuclear magnetic resonance logging instrument while drilling |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5923167A (en) * | 1992-07-30 | 1999-07-13 | Schlumberger Technology Corporation | Pulsed nuclear magnetism tool for formation evaluation while drilling |
US5929732A (en) * | 1997-04-17 | 1999-07-27 | Lockheed Martin Corporation | Apparatus and method for amplifying a magnetic beam |
US6246236B1 (en) * | 1998-03-03 | 2001-06-12 | Schlumberger Technology Corporation | Apparatus and method for obtaining a nuclear magnetic resonance measurement while drilling |
US6326784B1 (en) * | 1998-11-05 | 2001-12-04 | Schlumberger Technology Corporation | Nuclear magnetic resonance logging with azimuthal resolution using gradient coils |
CN201546719U (en) * | 2009-11-11 | 2010-08-11 | 中国海洋石油总公司 | Focusing nuclear magnetic resonance eccentric well-logging probe |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2939137B2 (en) * | 1994-09-29 | 1999-08-25 | 株式会社三協精機製作所 | Objective lens drive |
GB9716993D0 (en) * | 1997-08-11 | 1997-10-15 | Oxford Instr Ltd | Magnetic field generating assembly |
-
2012
- 2012-05-04 CN CN201210137281.6A patent/CN102650208B/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5923167A (en) * | 1992-07-30 | 1999-07-13 | Schlumberger Technology Corporation | Pulsed nuclear magnetism tool for formation evaluation while drilling |
US5929732A (en) * | 1997-04-17 | 1999-07-27 | Lockheed Martin Corporation | Apparatus and method for amplifying a magnetic beam |
US6246236B1 (en) * | 1998-03-03 | 2001-06-12 | Schlumberger Technology Corporation | Apparatus and method for obtaining a nuclear magnetic resonance measurement while drilling |
US6326784B1 (en) * | 1998-11-05 | 2001-12-04 | Schlumberger Technology Corporation | Nuclear magnetic resonance logging with azimuthal resolution using gradient coils |
CN201546719U (en) * | 2009-11-11 | 2010-08-11 | 中国海洋石油总公司 | Focusing nuclear magnetic resonance eccentric well-logging probe |
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