The housing of electromagnetic wave resistivity instrument
Technical field:
The invention belongs to the housing of oil drilling downhole testing instrument class, particularly a kind of electromagnetic wave resistivity instrument.
Background technology:
Measurement-while-drilling system LWD disposes electromagnetic wave resistivity instrument usually at present, and it can measure the resistivity geologic parameter on stratum, carries out hole trajectory control in view of the above.With boring electromagnetic resistivity is the primary difficult problem that LWD logs well, and realizes the measurement of electromagnetic resistivity near drill bit, owing to be subjected to the restriction of motor machinery and physical space, the structure design of its housing is extremely difficult especially.Measurement-while-drilling system adopts electric pole type to carry out the measurement of nearly drill bit resistivity usually both at home and abroad, and it is compared with the electromagnetic wave mode, and precision is low, applicable surface is narrow (can't measure in oil-base mud).
Summary of the invention:
In order to solve the problem that exists in the background technology, the invention provides a kind of housing of electromagnetic wave resistivity instrument, the present invention has overcome the restriction of motor machinery and physical space, in limited space, designed the shell structure of electromagnetic wave resistivity instrument, realized measuring nearly drill bit resistivity in the electromagnetic wave mode of precision height, suitable face width.
The technical solution adopted in the present invention is: the shell structure of this electromagnetic wave resistivity instrument comprises the pipe nipple body, the external wall of pipe nipple has groove, be fixed with the buckle closure body that the shape with groove matches in the groove, be separated with the antenna groove between the outer wall of buckle closure body, upper shed place of it wire casing is equipped with the antenna rib, the lower opening of it wire casing is equipped with pad, has cable hole on the pad, and the buckle closure inner body wall between adjacent two sky wire casings has mounting groove.
The beneficial effect that the present invention had is: the present invention adopts buckle closure formula structure, installs, convenient disassembly, has realized the execute-in-place of resistivity instrument; Housing seal is reliable, and resistance to compression reaches 35MPa; In limited space, realized the installation of the whole components and parts of resistivity instrument, and after the components and parts installation, it is little that electromagnetic wave signal receives interference; Realized the directionality measurement of resistivity; Overall construction intensity, resistance to shock height satisfy the abominable operating mode in down-hole.
Description of drawings:
Fig. 1 is a structural representation of the present invention
Fig. 2 is the upward view of buckle closure body among Fig. 1;
Fig. 3 is the front view of buckle closure body among Fig. 1;
Fig. 4 is the vertical view of buckle closure body among Fig. 1.
Among the figure: 1-pipe nipple body, 2-buckle closure body, 3-snap ring, 4-trip bolt, 5-antenna rib, 6-cable hole, 7-pad, 8-demounting tool screwed hole, 9-sealing ring, 10-days wire casing, 11-mounting groove.
The specific embodiment:
The present invention is further described below in conjunction with accompanying drawing: as shown in accompanying drawing 1, the housing of this electromagnetic wave resistivity instrument comprises pipe nipple body 1, pipe nipple body 1 outer wall has groove, be fixed with the buckle closure body 2 that matches with groove shape all around in the groove, be separated with antenna groove 10 between the outer wall of buckle closure body 2, upper shed place of it wire casing 10 is equipped with antenna rib 5, and day wire casing 10 both sides inwalls leave boss, and boss and two ends are that the antenna rib 5 of spill cooperates; The lower opening of it wire casing 10 is equipped with pad 7, and the 5 following sky wire casing 10 interior installations of antenna rib are launched, reception antennas, and the glue sealing is used in antenna installation back, uses pad 7 supports after the sealing; Have cable hole 6 on the pad 7, the circuit of antenna is drawn from the cable hole 6 on the pad 7; Buckle closure body 2 inwalls between adjacent two sky wire casings 10 have mounting groove 11, and mounting groove 11 forms big components and parts installing space with the wall groove of pipe nipple body 1, is separately installed with battery and circuit board in the mounting groove 11.The antenna that cable hole 6 from pad 7 is drawn is connected with circuit board.Buckle closure body 2 installed inside grooves 11 cooperate with the outer wall groove milling of pipe nipple body, form big components and parts installing space, and installing space is offset to the pipe nipple axis, and the measurement of resistivity has directionality.As shown from the above technical solution: resistivity instrument is placed on the wall of pipe nipple body 1, is not subjected to the restriction of motor machinery and physical space, and it is little that electromagnetic wave signal receives interference, improved measuring accuracy.
Antenna rib 5 can separated into two parts; antenna rib 5 two ends are respectively spill; be connected with the boss of wire casing 10 both sides, sky on the buckle closure body 2; gapped between antenna rib 5 and day wire casing 10 walls; electromagnetic wave sends from the gap between antenna rib 5 and day wire casing 10 walls, because subsurface environment is abominable, vibration is big; antenna rib 5 can effectively be protected antenna, does not influence electromagnetic wave again and sends.
In order to reach better sealing effectiveness, the edge is circumferentially with sealing ring 9 between pipe nipple body 1 and the buckle closure body 2.
In order to prevent that buckle closure body 2 breaks away from pipe nipple body 1, pipe nipple body 1 adopts trip bolt 4 and snap ring 3 double fixed with buckle closure body 2.For install, convenient disassembly, buckle closure body 2 is provided with demounting tool screwed hole 8.