کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8091328 1521994 2014 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Pressure effects caused by CO2 injection in the Tubåen Fm., the Snøhvit field
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Pressure effects caused by CO2 injection in the Tubåen Fm., the Snøhvit field
چکیده انگلیسی
1.6 Mt of CO2 was injected in the Tubåen Fm. at the Snøhvit field from April 2008 to April 2011. Injection was associated with a pressure build-up, and following a well intervention operation, the Stø Fm. was used for further CO2 injection, avoiding the pressure limitations in the Tubåen Fm. The pressure build-up in Tubåen Fm. was mainly caused by a limited reservoir volume and heterogeneities in the formation. Salt precipitation was evaluated as a possible source that reduced the near wellbore injectivity with associated pressure build-up. Weekly injection of a 90:10 mixture of methyl ethyl glycol and water (MEG) was implemented to mitigate salt precipitation. This paper evaluates the causes for the pressure build-up in more details. Analysis of bottom-hole-pressure measurements (BHP) from periods of shut in indicates a low permeable zone surrounding the well at early stage of injection. The low permeable zone may be caused by precipitated salt reducing the injectivity. Salt precipitation is also observed to reduce the porosity and permeability on core plugs from the injection well in laboratory measurements. The Tubåen Fm. comprise of 4 sandstone units (Tubåen 1-4) separated by interbedded shale units. Comparison between synthetic seismograms and time-lapse seismic data indicate that CO2 propagated into the three lowermost Tubåen sandstone units (Tubåen 1-3), where the pressure also increased. The shale unit above Tubåen 3 sandstone unit appears sealing from the synthetic seismograms. Tubåen 1 sandstone unit has exceptionally good injectivity. This may have a negative impact on the overall storage capacity by channeling the CO2 and increase the pressure locally. A dimming of the time-lapse seismic amplitude is observed that may be associated with the injected MEG.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Greenhouse Gas Control - Volume 27, August 2014, Pages 178-187
نویسندگان
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