Ascertainment of potential increase in production of RAG oil wells due to casing pressure drop

Nicole Engl

Research output: ThesisDiploma Thesis

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Abstract

Aim of this diploma thesis was to optimize production due to casing pressure reduction in brown field development which are on the decline by reason of decreasing reservoir pressure. When in an oil well a column of gas forms in the casing above the fluid level in the annulus, casing pressure increases. Due to this fact the evolving pressure hinders the hydrocarbons inflow into the well and so restricts the amount of oil and gas production. It is beneficial for the productivity of the well to lower the casing pressure and thus allow more hydrocarbons to flow into the wellbore. This raises the dynamic fluid level and thus production can be increased. In order to bleed off the casing pressure and increase productivity, a specific and profitable method is the beam mounted gas compressor technology. The principle is based on a big bicycle pump and draws the gas from the casing, compresses it and afterwards releases the gas into the flow line. A typical beam mounted gas compressor is attached on the walking beam of a pumping unit, and is operating either single-acting or double-acting. For lower casing gas volume applications a single-acting device is assembled. It draws gas from the casing during one half of the pumping unit stroke cycle and releases it during the second half. The double-acting option is used to fit higher gas volume applications It has two reservoirs that enable to draw gas in one reservoir and compress and release it in the other. This procedure takes place on the upstroke and the downstroke of the pumping unit. A beam mounted gas compressor utilizes the pumping unit as its prime mover and energy source. By moving the gas up the casing and away from the down hole pump it results in increasing pumping efficiency and also prevents gas locking. In order to determine an appropriate well for a beam mounted gas compressor, different screening criteria were made. Subsequent some software simulations were accomplished and the results could be verified with production tests. Finally, it should be noted that for an optimum evaluated candidate, this technology is a promising and economic system with limited investment and a short payout time.
Translated title of the contributionPotentialerhebung für mögliche Produktionssteigerungen bei RAG Ölsonden durch Druckabsenkung im Casing
Original languageEnglish
Supervisors/Advisors
  • Pham, Thanh Huong, Supervisor (external)
  • Hofstätter, Herbert, Supervisor (internal)
Award date18 Dec 2009
Publication statusPublished - 2009

Bibliographical note

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Keywords

  • beam mounted gas compressor casing pressure drop relieve casing pressure increase productivity single-acting double-acting ATEX-directive CE-certification multiphase pump short payback time

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