TY - THES

T1 - Design criteria and innovative solutions for workover concepts in mature EMPG gas fields

AU - Högn, Ludwig

N1 - embargoed until 29-10-2018

PY - 2013

Y1 - 2013

N2 - This master thesis contains an analysis of the technical fundaments for natural gas workover concepts, which are important for the production out of depleted reservoirs. To this regard, common completion designs and the possible procedures which are important in the tail-end phase for deliquification of condensed water and other reservoir fluids are being evaluated. First of all, the theoretical conditions of intermittent production, which lead to a liquid load-up, are described. In the following chapter, a sensitivity analysis is performed, based on a representative natural gas well in Northern Germany, which is operated by ExxonMobil Production Germany, to determine the influence of various factors and their importance. Another chapter is dealing with possibilities of an artificial discharge of accumulating water in the wellbore, via artificial lift systems and their applicability on wellbores operated by EMPG. Their specific composition poses major limitations in possible applications; hence the gained insights are also included in order to carry out a future installation of artificial lift systems cost-effectively. A discussion concerning the installation of a chemical injection line and the end of tubing is also essential for the completion of design, because it cannot be changed later. The conclusion, which is based on the findings of the sensitivity analysis, the possible artificial lift systems and the life-cycle costs were finally applied for three wellbores, which are workover candidates in the years 2013 and 2014.

AB - This master thesis contains an analysis of the technical fundaments for natural gas workover concepts, which are important for the production out of depleted reservoirs. To this regard, common completion designs and the possible procedures which are important in the tail-end phase for deliquification of condensed water and other reservoir fluids are being evaluated. First of all, the theoretical conditions of intermittent production, which lead to a liquid load-up, are described. In the following chapter, a sensitivity analysis is performed, based on a representative natural gas well in Northern Germany, which is operated by ExxonMobil Production Germany, to determine the influence of various factors and their importance. Another chapter is dealing with possibilities of an artificial discharge of accumulating water in the wellbore, via artificial lift systems and their applicability on wellbores operated by EMPG. Their specific composition poses major limitations in possible applications; hence the gained insights are also included in order to carry out a future installation of artificial lift systems cost-effectively. A discussion concerning the installation of a chemical injection line and the end of tubing is also essential for the completion of design, because it cannot be changed later. The conclusion, which is based on the findings of the sensitivity analysis, the possible artificial lift systems and the life-cycle costs were finally applied for three wellbores, which are workover candidates in the years 2013 and 2014.

KW - Kompletierungsarbeiten

KW - Aufwältigungsarbeiten

KW - Druckschwache Gas Reservoire

KW - Artificial Lift Systems Workover

KW - Completion Engineering

KW - Workover

KW - Mature gas fields

KW - Artificial lift systems

M3 - Master's Thesis

ER -