SDS Telemetry System

The SDS Telemetry System consists of a Simple Telemetry Board (STB) and an optional Downhole Power Supply Board (DHPS) . The purpose of the STB is to convey data from downhole tools on the tool bus (RS232), Transmit/Receive the data and Commands to/from the surface via a reliable digital telemetry system facilitating communication between the Warrior Surface System and downhole tools. Typical applications have been for conventional logging tools (including digital acoustic and spectral data), hybrid tools (telemetry and memory simultaneously), intervention tools (relying heavily on surface to downhole control) and fast mobilization for the development of new tools and sensor testing where "off the shelf" and simple to setup and interface telemetry can save substantial development time and costs.

SDS Simple Telemetry Circuit Board (STB)

General Specifications: Maximum Temperature 350ºF (177°C), operating Voltages (dependent on power supply) range +0 +450V DC, Current consumption at 200V 15mA, Tool Bus data rate 115kbps, Wireline Uplink data rates currently 12 kbps to 67 kbps, and Downlinks rates 1 kbps to 5 kbps. Input Voltage Requirements are typically +15Vdc, -15Vdc and +5Vdc.

SDS Simple Telemetry circuit Board (STB)

The STB consists of 5 main functional blocks as shown in the block diagram below

SDS STB block diagram

Wireline Uplink Modem

The Wireline Uplink Modem forms the hardware interface between the Rx Tool Bus RS232 Modem and the Wireline mono-cable which transmits data to the surface system. Uplinks are modulated onto the line as pulsed RS232 at a selectable bit rate currently ranging from 12 kbps to 67 kbps with amplitude of +/- 15Vpk. The Wireline Uplink Modem rate can be changed via downlink command. The Wireline Uplink Modem uses half duplex transmission.

Rx Tool Bus RS232

The Rx Tool Bus RS232 Modem forms the hardware interface between the Downhole Tools and Wireline Uplinks Modem. Rx is modulated TTL input (5Vdc), onto Rx Tool Bus RS232 Modem at 115kbps. The Rx Tool Bus RS232 Modem rate can be change for downlinks commands via I2C Bus.

Wireline Downlink Modem

A half duplex downlink allows the user to configure and control operations from the surface prior to and during logging. Control is exercised by means of commands, which may be destined for the Wireline Downlink Modem, Rx Tool Bus RS232 Modem, and /or passed on to other tools via the Tx Tool Bus RS232 Modem. Where command execution generates a response, this is generally uplinked to the surface via Wireline Uplinks Modem, downlink status is monitored and reported by the system.

Tx Tool us RS232 Modem

The Tx Tool Bus RS232 Modem forms the hardware interface between the Wireline Downlinks Modem and the Downhole Tools. Tx is modulated TTL output, onto the Tool Bus as RS232 at 115kbps (5Vdc). The Tool Bus rate can be changed for downlinks commands via I2C bus.

Analog Bus Inputs

The Analog Bus Inputs received signals between 0 to 4 VDC. The Tool Head Voltage, Internal Downhole Temperature, and Tool Bus Voltage are sensed and sent to the surface to facilitate setting the appropriate operating voltage.

SDS Simple Telemetry Board Specification:

Uplink Data Rate over Wireline

50 Kbits/sec (on most cables); actual rate controlled from surface

Downlink Data Rate over Wireline

5 Kbits/sec

Tool Bus

RS232 serial port at logic levels (3.3V to 5.0V); rate configurable but aggregate must be lower than the selected wireline rate.

Power Requirements

Plus/minus 12VDC to 15VDC and +5VDC

Temperature Rating

177°C (350°F) for 1 hour

Board Dimensions

7.5 inches x 1.25 inches

SDS Downhole Power Supply (DHPS)

The nominal input voltage (Line) is 200VDC, with a range 180VDC to 250VDC, the line is filtered with LC circuit to avoid the noise in the telemetry. The PWN Controller has a fixed switching frequency of the 100 KHz in current mode with automatic symmetry correction for push-pull converter. The power supply has over output voltage, and current limit protection. The maximum output voltage is 24VDC/1.0A.

SDS Downhole Power Supply (DHPS) Board

(DHPS) Board Dimensions

There are three high efficiency synchronous step-down regulators. The input voltage is 24VDC and the outputs voltages are +15VDC@100mA, -15VDC@100mA, and +5VDC@200mA. The Cable Head Voltage 200VDC (LINE) is sample (HV_S) @2VDC. The Tool Power Bus Voltage 24VDC is sample (LV_S) @2.4VDC, those outputs signal are send to telemetry board. The maximum temperature is 177°C (350°F).

Downhole Power Supply Block Diagram

SDS Power Supply Board Specification:

Head Voltage (Input)

180-270 VDC

Outputs

Plus/minus 15VDC @ 100ma and +5VDC @ 200ma (normally for telemetry board) 24VDC @ 1.0A general purpose. Higher output is possible with use of chassis mount components.