TY - THES

T1 - Process and Procedure for Gas Well Deliquification

AU - Kulagina, Anna

N1 - embargoed until 21-02-2022

PY - 2017

Y1 - 2017

N2 - In the production of natural gas, along with gas, a small amount of liquid is produced. The liquids produced along with gas may have varying sources which depend on the condition and type of the reservoir: 1. There may be an aquifer underneath the gas zone which may either lead to water coning or water cusping. 2. The origin of liquids may be another zone (or zones) than from the produced/perforated horizon (e.g. flow behind pipes, well integrity issues) 3. The water produced may be condensed or free water present in the formation. Towards the maturity of gas wells the production rate decreases due to decreasing bottom-hole pressure (depletion), which leads to a lower production velocity resulting in an inability to carry liquids to the surface. When these liquids aren’t completely removed from the well with the gas production flow, they can accumulate downhole, causing the gas to flow intermittently, lowering production and eventually killing the well. This issue is called liquid loading and at this point the liquids must be artificially removed. As liquid loading occurs it is crucial to recognize the problem at early stages and select a suitable prevention method. There are 6 main methods to prevent liquid loading such as: 1. Tubing sizing to increase velocity (e.g. velocity string design) 2. Decrease Wellhead flowing pressure (e.g. compression) 3. ESP and positive displacement lift systems 4. Fluid power / Gas lift systems 5. Foam lift systems 6. Plunger lift systems This project is aimed at describing the methodologies & examples of best practise to identify, qualify and to mitigate liquid loading issues in gas wells within an OMV process and procedures document for gas well deliquification.

AB - In the production of natural gas, along with gas, a small amount of liquid is produced. The liquids produced along with gas may have varying sources which depend on the condition and type of the reservoir: 1. There may be an aquifer underneath the gas zone which may either lead to water coning or water cusping. 2. The origin of liquids may be another zone (or zones) than from the produced/perforated horizon (e.g. flow behind pipes, well integrity issues) 3. The water produced may be condensed or free water present in the formation. Towards the maturity of gas wells the production rate decreases due to decreasing bottom-hole pressure (depletion), which leads to a lower production velocity resulting in an inability to carry liquids to the surface. When these liquids aren’t completely removed from the well with the gas production flow, they can accumulate downhole, causing the gas to flow intermittently, lowering production and eventually killing the well. This issue is called liquid loading and at this point the liquids must be artificially removed. As liquid loading occurs it is crucial to recognize the problem at early stages and select a suitable prevention method. There are 6 main methods to prevent liquid loading such as: 1. Tubing sizing to increase velocity (e.g. velocity string design) 2. Decrease Wellhead flowing pressure (e.g. compression) 3. ESP and positive displacement lift systems 4. Fluid power / Gas lift systems 5. Foam lift systems 6. Plunger lift systems This project is aimed at describing the methodologies & examples of best practise to identify, qualify and to mitigate liquid loading issues in gas wells within an OMV process and procedures document for gas well deliquification.

KW - gas well

KW - deliquification

KW - tubing sizing

KW - velocity string

KW - ESP

KW - gas lift

KW - foam lift

KW - plunger lift

KW - deliquification

KW - tubing sizing

KW - velocity string

KW - ESP

KW - gas lift

KW - foam lift

KW - plunger lift

M3 - Master's Thesis

ER -