Enhancement of Vorwata Field Reservoir Model by Integration of Pressure Transient Analysis with Real-Time Downhole Pressure Data

2011 ◽  
Author(s):  
Agus Setiawan ◽  
Kirk Hird ◽  
Curtis Owen Bennett
Keyword(s):  
Real Time ◽  
Transient Analysis ◽  
Pressure Data ◽  
Reservoir Model ◽  
Pressure Transient Analysis ◽  
Pressure Transient

Delivering Pressure Transient Analysis During Drawdown on ESP Wells: Case Studies and Lessons Learned

2021 ◽  
Author(s):  
Lawrence Camilleri ◽  
Mohammed Al-Jorani ◽  
Mohammed Kamal Aal Najar ◽  
Joseph Ayoub
Keyword(s):  
Real Time ◽  
Case Studies ◽  
Flow Rate ◽  
High Frequency ◽  
Transient Analysis ◽  
Continuous Production ◽  
Complete Analysis ◽  
Pressure Transient Analysis ◽  
Pressure Transient ◽  
Production History

Abstract While pressure transient analysis (PTA) is a proven interpretation technique, it is mostly used on buildups because drawdowns are difficult to interpret. However, the deferred production associated with buildups discourages regular application of PTA to determine skin and identify boundary conditions. Several case studies are presented covering a range of well configurations to illustrate how downhole transient liquid rate measurements with electrical submersible pump (ESP) gauges enable PTA during drawdown and therefore real-time optimization. The calculation of high-frequency transient flow rates using ESP gauge real-time data is based on the principle that the power absorbed by the pump is equal to that generated by the motor. This technique is independent of fluid specific gravity and therefore is self-calibrating with changes in water cut and phase segregation. Analytical equations ensure that the physics is always respected, thereby providing the necessary repeatability. The combination of downhole transient high-frequency flow rate and permanent pressure gauge data enables PTA using commonly available analytical techniques and software, especially because superposition time is calculated accurately. The availability of continuous production history brings significant value for PTA. It makes it possible to perform history matching and to deploy semilog analysis using an accurate set of superposition time functions. However, the application of log-log analysis techniques is usually more challenging because of imperfections in input data such as noise, oversimplified production history, time-synchronization issues, or wellbore effects. These limitations are solved by utilizing high-frequency downhole data from ESP. This is possible first as superposition time is effectively an integral function, which dampens any noise in the flow rate signal. Another important finding is that wellbore effects in subhydrostatic wells are less impactful in drawdowns than in buildups where compressibility and redistribution can mask reservoir response. Key reservoir properties, in particular mobility, can nearly always be estimated, leading to better skin factor determination even without downhole shut-in. Finally, with the constraint of production deferment eliminated, drawdowns can be monitored for extended durations to identify boundaries and to perform time-lapse interpretation more efficiently. Confirming a constant pressure boundary or a change in skin enables more effective and proactive production management. In all cases considered, a complete analysis was possible, including buildup and drawdown data comparison. With the development of downhole flow rate calculation technology, it is now possible to provide full inflow characterization in a matter of days following an ESP workover, without any additional hardware or staff mobilization to the wellsite and no deferred production. More importantly, the technique provides the necessary information to diagnose the cause of underproduction, identify stimulation candidates, and manage drawdown.

scholarly journals Real-Time Computer Analytical Application in Pressure Transient Analysis of Petroleum Reservoirs

2013 ◽  
Vol 04 (08) ◽  
pp. 1186-1192
Author(s):  
Kanya Khatri ◽  
Sadiq A. Shah ◽  
Agha F. H. Pathan ◽  
Bilal Shams ◽  
Ashfaque A. Memon ◽  
...  
Keyword(s):  
Real Time ◽  
Transient Analysis ◽  
Petroleum Reservoirs ◽  
Analytical Application ◽  
Pressure Transient Analysis ◽  
Pressure Transient

State of the Art in Characterization of Frac Stage Geometry and Conductivity Using Pressure Leakoff

2021 ◽  
Author(s):  
Mohamed Ibrahim Mohamed ◽  
Erdal Ozkan
Keyword(s):  
Hydraulic Fracturing ◽  
Hydraulic Fracture ◽  
Transient Analysis ◽  
State Of The Art ◽  
Low Cost ◽  
Pressure Data ◽  
Pressure Transient Analysis ◽  
Fracture Conductivity ◽  
Pressure Transient ◽  
Half Length

Abstract Pressure-transient analysis (PTA) is widely used in the industry to estimate fracture half-length, height, and skin due to hydraulic fracturing as well as reservoir parameters. PTA studies focus on pressure data from long shut-in periods and diagnostic fracture injection tests (DFITs), while analyzing the pressure data recorded during the hydraulic fracture treatment has been overlooked. This paper details the state-of-the-art in applying pressure transient analysis to better estimate hydraulic fracture conductivity and dimensions and improve treatment designs stage by stage. The initial portion of this paper describes the application of a novel and low-cost diagnostic method for post-fracture analysis. The bulk of the paper is dedicated to present case histories that illustrate the PTA of the recorded pressure data during treatment to obtain estimates of fracture dimensions and conductivity. The pressure recorded during each stage is processed to ensure the proper data quality and the pressure falloff at the end of the stage is filtered out. The pressure is then analyzed for multi-cluster, finite-conductivity fractures, to obtain the fracture half-length, conductivity, and leakoff. Calculated parameters from each stage are compared to provide insights into the hydraulic fracture design and confirm the adequacy of the treatment design along the well. The results from stage leakoff pressure analysis are very valuable in confirming relative fracture conductivity and providing a qualitative measure of fracture length and height. The total stimulated reservoir area (SRA) calculated using the proposed method yields comparable values to SRA obtained from buildup analysis. The information provided is as valuable and comparable as that from direct near-wellbore diagnostics, such as radioactive traces, temperature logging, real-time micro-seismic monitoring, and production logging. The paper proposes a novel, low-cost analytical PTA method for estimating fracture dimensions, skin, and leakoff coefficient. We illustrate – with several field cases – that conventional post-fracture techniques can be integrated with the stage by stage PTA analysis to provide not only a more consistent and systematic analysis but also a more accurate assessment of treatment effectiveness. The findings of this paper help improve the efficiency of multistage hydraulic fracturing stimulation of horizontal wells.

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