TY - THES

T1 - Evaluation of Mature Gas Fields in the Detfurth Formation in Northern Germany for the Possibility of Deploying Wellhead Compression to Extend Economical Natural Gas Production

AU - Thurmaier, Antonia

N1 - embargoed until 13-03-2022

PY - 2017

Y1 - 2017

N2 - Most gas fields in Europe are already in their last stage of production, the so-called tail-end phase. Several problems arise as the fields mature, liquid loading being one of the main challenges. It explains the process of liquids accumulating at the bottom of the wellbore, leading to a loss in production, potentially resulting in the death of the well or even the reservoir. This thesis discusses functional methods to identify liquid loading in gas wells even during its early stages, when it is often difficult to recognize. Practical techniques were introduced, which allow one to forecast future liquid loading scenarios, along with the theoretical principles behind them. A variety of techniques to prevent liquid loading was presented. The physical tenets of the diverse systems were discussed. Furthermore, the practical application principles were introduced, followed by restrictions of the systems, identifying advantages and disadvantages along the way. This thesis focusses on the application of wellhead compression, which is an established gas well deliquification method. Lowering the wellhead pressure does not only increase the gas production, but also prevents the occurrence of liquid loading, potentially enhancing the recoverable gas reserves. A screening of possible well candidates was conducted to evaluate an eventual future application of wellhead compression for the gas fields of Wintershall in the Detfurth formation in northern Germany. Several screening criteria were introduced to rank the potential well candidates objectively in order to identify an ideal trial well for wellhead compression. The theoretical principles of compression were outlined and the different compressor types commonly used for wellhead compression were described. A market analysis was conducted to explore various compressor systems in order to find an ideal fit for the gas wells. In addition to the technical evaluation, an economic analysis was carried out to verify whether the systems are commercially feasible or not. Finally, the HSE- relevant aspects related to applying wellhead compression, including environment, plant safety and reputation aspects, were discussed. At the end a recommendation for further deployment of wellhead compression in Wintershall’s mature gas fields in northern Germany was drafted.

AB - Most gas fields in Europe are already in their last stage of production, the so-called tail-end phase. Several problems arise as the fields mature, liquid loading being one of the main challenges. It explains the process of liquids accumulating at the bottom of the wellbore, leading to a loss in production, potentially resulting in the death of the well or even the reservoir. This thesis discusses functional methods to identify liquid loading in gas wells even during its early stages, when it is often difficult to recognize. Practical techniques were introduced, which allow one to forecast future liquid loading scenarios, along with the theoretical principles behind them. A variety of techniques to prevent liquid loading was presented. The physical tenets of the diverse systems were discussed. Furthermore, the practical application principles were introduced, followed by restrictions of the systems, identifying advantages and disadvantages along the way. This thesis focusses on the application of wellhead compression, which is an established gas well deliquification method. Lowering the wellhead pressure does not only increase the gas production, but also prevents the occurrence of liquid loading, potentially enhancing the recoverable gas reserves. A screening of possible well candidates was conducted to evaluate an eventual future application of wellhead compression for the gas fields of Wintershall in the Detfurth formation in northern Germany. Several screening criteria were introduced to rank the potential well candidates objectively in order to identify an ideal trial well for wellhead compression. The theoretical principles of compression were outlined and the different compressor types commonly used for wellhead compression were described. A market analysis was conducted to explore various compressor systems in order to find an ideal fit for the gas wells. In addition to the technical evaluation, an economic analysis was carried out to verify whether the systems are commercially feasible or not. Finally, the HSE- relevant aspects related to applying wellhead compression, including environment, plant safety and reputation aspects, were discussed. At the end a recommendation for further deployment of wellhead compression in Wintershall’s mature gas fields in northern Germany was drafted.

KW - Wellhead Compression

KW - Liquid Loading

KW - Critical Velocity

KW - Nodal Analysis

KW - mature

KW - Gasfield

KW - Natural Gas

KW - Compressor

KW - Wellhead Compression

KW - Bohrlochkopf-Kompression

KW - kritische Geschwindigkeit

KW - Liquid Loading

KW - Nodal Analysis

KW - Kompressor

M3 - Master's Thesis

ER -