TY - THES

T1 - Study and Performance Evaluation of Wellbore Perforating Systems

AU - Sirghii, Viorica

N1 - embargoed until 15-06-2022

PY - 2017

Y1 - 2017

N2 - In the life cycle of any oil and gas wells there are certain points where decisions and events will ultimately define the success or failure of the productivity of the well. Although there can be an extensive list of factors, one of the elemental key operations of any well is the last point of connection to the reservoir and in a large majority of wells this involves the detonation of a deployed high energy explosive charge at the designated productive layer. Known as perforation, the operation is a step in the well completion process and creates the flow path of the reservoir fluids into the production wellbore. A special consideration is given to the design of the perforating procedure in order to provide a completion plan that can enhance the final productivity based on industry benchmarks. The objective of this study was to optimize all the factors involved in ensuring the maximum flow from specific reservoirs and to compare theoretical applications with practical results and provide continuous improvement. This study provides a comprehensive overview of the perforation process and its techniques and the various influencing factors which exist in Brown Field environments like those in OMV Petrom. As a result of the comparative analysis, it was found that theoretical results given by simulation software used for predicting the well performance as a function of perforating operations quality are significantly overestimated compared to real data. Such an overestimation comes from the fact that these programs do not take into consideration more detailed reservoir properties and the standard testing conditions on which the calculation is based do not correspond to real borehole and formation characteristics. Such results can lead to erroneous expectations about the future well performance and perforating efficiency. However, it should be taken into consideration that software has its limitations and the aim was to have a reference from various suppliers and have a comparison. Future research should be oriented in acquiring more qualitative reservoir data and understanding the relevant knowledge and information that we have about the particular well and reservoir and improving the analysis by using more complex computer programs. The further results should aid the implementation of a customized perforating philosophy, which means having a per layer insight for every reservoir. This is of significant importance for both economical and production efficiency analysis of the well.

AB - In the life cycle of any oil and gas wells there are certain points where decisions and events will ultimately define the success or failure of the productivity of the well. Although there can be an extensive list of factors, one of the elemental key operations of any well is the last point of connection to the reservoir and in a large majority of wells this involves the detonation of a deployed high energy explosive charge at the designated productive layer. Known as perforation, the operation is a step in the well completion process and creates the flow path of the reservoir fluids into the production wellbore. A special consideration is given to the design of the perforating procedure in order to provide a completion plan that can enhance the final productivity based on industry benchmarks. The objective of this study was to optimize all the factors involved in ensuring the maximum flow from specific reservoirs and to compare theoretical applications with practical results and provide continuous improvement. This study provides a comprehensive overview of the perforation process and its techniques and the various influencing factors which exist in Brown Field environments like those in OMV Petrom. As a result of the comparative analysis, it was found that theoretical results given by simulation software used for predicting the well performance as a function of perforating operations quality are significantly overestimated compared to real data. Such an overestimation comes from the fact that these programs do not take into consideration more detailed reservoir properties and the standard testing conditions on which the calculation is based do not correspond to real borehole and formation characteristics. Such results can lead to erroneous expectations about the future well performance and perforating efficiency. However, it should be taken into consideration that software has its limitations and the aim was to have a reference from various suppliers and have a comparison. Future research should be oriented in acquiring more qualitative reservoir data and understanding the relevant knowledge and information that we have about the particular well and reservoir and improving the analysis by using more complex computer programs. The further results should aid the implementation of a customized perforating philosophy, which means having a per layer insight for every reservoir. This is of significant importance for both economical and production efficiency analysis of the well.

KW - perforating systems

KW - standards

KW - analysis

KW - performance

KW - comparison

KW - software

KW - efficiency

KW - optimization

KW - economics

KW - design

KW - success

KW - Perforieren

KW - Standards

KW - Analyse

KW - Performance

KW - Vergleich

KW - Software

KW - Effizienz

KW - Optimierung

KW - Wirtschaft

KW - Design

KW - Erfolg

M3 - Master's Thesis

ER -