Telemetry Exam 43 Questions with Verified Answers
Telemetry definition - CORRECT ANSWER Highly automated communication process by which measurements and other collected data at remote or nonaccessible points re made a
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Telemetry Exam 43 Questions with Verified Answers
Telemetry definition - CORRECT ANSWER Highly automated communication process by which measurements and other collected data at remote or nonaccessible points re made and transmitted to receiving equipment for monitoring
Modulation - CORRECT ANSWER Reinterpretation and translation of signals using amplitude and/or frequency
Bandpass modulation - CORRECT ANSWER Uses carrier frequency
Baseband modulation - CORRECT ANSWER Does not use carrier frequency
Digital modulation methods - CORRECT ANSWER Quadrature phase shift keying (varying phase only); quadrature amplitude modulation (varies phase and amplitude)
QPSK (Quadrature Phase Shift Keying) - CORRECT ANSWER A form of PSK; it uses four different carrier phases (45 degrees, 90 degrees, 180 degrees, and 270 degrees) to represent two data transmission bits. (i.e. 00 - 0 degrees; 01 - 90 degrees)
Transmission modes - CORRECT ANSWER Unidirectional (simplex) or bidirectional (half duplex or full duplex 4 wire circuit, ideal for WL)
Thruput - CORRECT ANSWER Number of bits/sec depending on paths for data transmission (data rate)
Baud rate - CORRECT ANSWER Number of symbols per second (symbol may have more than 2 states)
Frame Rate - CORRECT ANSWER Time is takes to complete full round of system's processing tasks
Cyclic Redundancy Check - CORRECT ANSWER Transmitted messages divided into predetermined lengths that are divided by fixed divisor; remainder is appended and sent with message and error detected if remainder not identical
AC Main Lines (Hepta) - CORRECT ANSWER 1-4 in cable and 1-4 in tool
EMEX Lines (Hepta) - CORRECT ANSWER DC power used in USIT/ FMI powered by TDI; new current superimposed on AC already flowing through transformer; lines 1-4, 10 in cable and x, 10 in tool
Phantom technique - CORRECT ANSWER Allows 1-4 lines to be used as AC main and EMEX at same time
AC Aux (hepta) - CORRECT ANSWER Cable: 2&6, 3&5 in parallel + 10, Line: 2-10
T5 Mode - CORRECT ANSWER Transmitter induces current on 2 closed loops and picks up in receiver circuit; lines 2,3,5,6; transmit signals by DTC, TCC UL/DL, and EDTC-A UL
T7 Mode - CORRECT ANSWER Analog (SP, CCL) signals on line 7 returning to 10, tied to cables 1-6; unbalanced mod= more sensitive to noise; DTC UL and EDTC DL
Data transmission modes options - CORRECT ANSWER T5 and T7, T5 only, T7 only
CTS - CORRECT ANSWER Cable Telemetry System; cables 12K-30K ft; uses TF mode in balanced pairs; half duplex; lines 25, 27, and 28 to be terminated with 56ohm to ground; data from top to bottom
DTB - CORRECT ANSWER Downhole tool bus: full duplex communication between CTS tools; 25, 27, 28 lines terminated with 56ohm resistor via line 16; short lines 28 and 29 together above TCC; if no other units below must be terminated with DTB, CCS bottom tools, AIT-H, HTBC
TCC clock signal - CORRECT ANSWER Travels in UP direction first
FTB tools in CTS - CORRECT ANSWER Fixed address hard coded during manufacturing
DTS - CORRECT ANSWER Digital telemetry system: use T5 downlink and QAM T5/T7 uplink (6 to 30Hz); data sent from bottom to top; IP from top to bottom; half duplex; external termination not needed for FTB tools; each tool with one IP
Top tool in DTS toolstring - CORRECT ANSWER DTC
Bandwidth Allocation of DTS based on - CORRECT ANSWER Uplink thruput (T5 only or T5/T7 and variable transmission rate); Downlink thruput (T5, fixed rate); Latency requirement of toolstring
FTB - CORRECT ANSWER Fast Tool bus, lines 5 and 6 (single twin twisted coax conductors), doesn't require external termination (autoterminated); interconnects IPs; improved noise immunity
IP - CORRECT ANSWER Interface Package: 16 max IPs, DTC takes first 2; 14 max can be combined; digital port consisting of 8bit parallel bus, read and write strobes and handshake lines
Which tool has shortest delay in DTC? - CORRECT ANSWER Bottom tool; packets of info from tools send as tool delays expire and transceiver changes into down position; each packet sent twice--IP checks both and keeps one without error
Superpacket - CORRECT ANSWER Compiled packet of lower tool data in DTC memory; after all packets received by DTC, composed into Superpackets; maximum of 32 ; uplink and downlink repeats every 16ms; each packet 1018 words maximum UL; only one superpacket sent DL w/ 1017 words maximum
Frame synchronization - CORRECT ANSWER FTB frame fixed, cable frame asynchronous varying from 6-30 Hz
Power transmission below DTC - CORRECT ANSWER AC Main through lines 1 and 4, AC aux through 2 and 10
DTC - CORRECT ANSWER DTC-H is newer, DTC-A not compatible with DTPC; internal measurements of head voltage, cartridge temp, and head tension (lines 14&15, 19 and 20); Tool Ops Recorder
DTPC - CORRECT ANSWER Digital Telemetry Power Cartridge: 2.5x more cartridge power (>0.9A)==SWAPS MAIN and AUX; can be above DTC; superphantom technique (EMEX still with AC Main but now on 2,3,5,6--1 and 4 free to send bigger Aux signal, also preventing induced noise)
EDTA - CORRECT ANSWER Enhanced Downhole Tool bus adaptor: allows both FTB and DTB tools by converting from CTS to DTS (converts DTB to FTB/ EFTB)
Baud rate for systems - CORRECT ANSWER TCC- 100kbps
FTB- up to 500 kbps using QAM
If CTS tools are at bottom - CORRECT ANSWER DTA must be above topmost CTS tool (CCS BN-DTB tools-DTA- FTB tools- DTC- Head)
If CTS tools at top - CORRECT ANSWER Must be FTB through wired AND termination for DTB bus is needed (ie HTBC) ex FTB tools- HTBC- DTB tools- DTA- DTC- Head
EDTS - CORRECT ANSWER enhanced digital telemetry system-- uses eftb and edtc; 63 tools (FTB ut15 + EFTB); T5 UL and T7 DL full duplex; 2 Mbs max data rate;
EFTB - CORRECT ANSWER Uses lines 5 nd 6, fully compatible with FTB; must be above FTB in order to mAINTAIN 2Mbs (otherwise, only 1 Mbs)
Expert mode - CORRECT ANSWER Can be reached in MW shop or aquisition; contains performance; buffer normally 43%
EDTS 2.0 - CORRECT ANSWER Only ewafe; 15 tools w FTB and 32 w eftb; UL 3.3 mbs
CAN bus - CORRECT ANSWER Lines 27 and 28 (can't guide DTB lines bc same lines)
monocable - CORRECT ANSWER can with psp, dtb with cplt
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