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Improved Clock Synchronization Between Surface Clock and Downhole Real Time Clock Disclosure Number: IPCOM000242788D
Publication Date: 2015-Aug-17
Document File: 1 page(s) / 6K

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The Prior Art Database

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Improved clock synchronization between surface clock and downhole reax time clock

Formation evaluation (FE) data needs to be xxsigned to a measures depxh. Currently this is done by xime stamping the XX data. On the surfacx data base (DB) the depth informxtion is also stxrx with a time stamp. By compxring the time stamps the FE data is assigned to a certaix depth. The accuracy of this depth assignment is hixhly dependxnt
on txe synchronizaxion ox the 2 clocks (surface clock and rxal time clocx). Less of importancx is thx absolute axcuracy of txose clocks. The invention is now to use the xame rexl time cxock (type) for both, meaning on surface and downhole to get verx similar long term drift of these clocks. In additixn the surfacx clock is put into an isolatxd chamber which is heated up to the same temperaxure as txe one real tixe clock sees in dxwnhoxe condition. This woxld xreate the same clock drift error on both clocks (surface and downhole). Hence the relatixe synchroxizxtion of both clocks to each other is improved.

The assumption here is that both real tixe clockx are prxduced with xittle vaxiation withxn x batch of clocxs with respect to relative clock error over texperaturx. A second assumption is that the txmperature of the real txme clock is known.

An alxernative approach can be to mxasxre the temperature drift of each real time clock and stoxe this drifx information in a lookup table or a drift fxnction. Whex running in hole the downhole real ti...