ÇAĞRILI KONUŞMALAR / KEYNOTES Invited Speeches ... - TPJD

Detection and Utilization of Volatile Organic Compounds in Drill Cutting
Samples Prior to Well Testing and Completion: A Preliminary Study
Kadir Gürgey 1 , Al H. Silliman 2 , Tuba Evren Sökmensüer 1 , Müjdat İşçi 1
1 Merty Energy, Ankara
2 W.L. Gore & Associates,Inc. Md, USA
Prior to well testing and completion efforts; detection of hydrocarbon rich reservoir (HRR) intervals,
vertical continuity between HHR intervals, hydrocarbon types (normal oil, heavy oil, natural
gas, condensate, solid bitumen etc.,) and quality (API gravity, occurrence of biodegradation)
which have long been done with assessment of well log, core sample and drill stem tests.
These operations, however, if the number of HRR intervals is greater than 1-2 (sometimes, HRR
number>10) are very expensive particularly in offshore basins such as in Gulf of Mexico Basin
in U.S.A., South Caspian Basin in Azerbaijan and Bohai Bay Basin in China and in onshore basins
such as in Gediz Graben Basin in Turkey etc. For this reason, a reduction of the expenses made
prior to well testing and completion was planned and parallel to the purpose, volatile organic
compound (VOC) and semi-VOC (SVOCs) present in the drill cuttings were thought to be useful.
In this study a total of 329 drill cutting samples were collected along the Sarıkız-2 (for every 15
m.) and -3 oil (for every 3m.) wells drilled in Alasehir, Gediz Graben of western Turkey. These
cutting samples were then subjected to passive treatment with GORE Modules that use unique
adsorbents to adsorb VOC and SVOCs in the range of C2 to C20. GORE modules were analyzed
by thermal destruction/gas chromatography/mass spectrometry (TD/GC/MS) to detect over 45
VOC and SVOCs in a ng (10-9 g) level. An assessment of the GORE data (329 samples x 45
variable) with both conventional and statistical methods gave the following preliminary however
encouraging results:
1) Detection of HRR intervals is possible,
2) For well testing purposes, HRR intervals can be ranked from significant to insignificant,
3) Vertical continuity between HHR intervals can be determined,
4) Seal rock efficiency can be checked,
5) Up-dip migration front can be estimated and
6) Hydrocarbon type and quality in HHRI can be approximated.
Regardless of the successful results obtained in this study, the technique do not replace
conventional methods yet, however do complement and enhance traditional approaches.
Keywords: Volatile organic compound, hydrocarbon rich interval, drill cutting
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