Production Analysis PA and Application of Rate Transient Analysis RTA in Carbonate Oil Reservoirs for Reservoir Characterization and Connectivity

Motaei, Eghbal; Ataei, Abdolrahim; Ebrahim, Yazdi Mohammad

doi:10.4043/28348-ms

Cited by 3 publications

(1 citation statement)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several studies also enriched the analytical models to more complex problems, such as the twophase flow in retrograde gas and condensate oil reservoirs, and early-time two-phase flow back data analysis [29,30]. Some studies also use this concept to approximately analyze the production data for wells with fracture interference [12,[31][32][33]. The slopes exhibited by the pressure and rate curves on the log-log plots are used to diagnose the well interference.…”

Section: Introductionmentioning

confidence: 99%

A Semianalytical Model for Analyzing the Infill Well-Caused Fracture Interference from Shale Gas Reservoirs

Fang

Dai

et al. 2021

Geofluids

View full text Add to dashboard Cite

Drilling infill well has been widely used in many plays to enhance the recovery of shale gas, but the infill well-caused fracture interference is a very important issue that should be taken into consideration. The well interference makes it difficult for the conventional models to make production predictions, fracture characterization, and production data analysis. In this paper, a semianalytical model is proposed for this purpose by discretizing the whole control volume of the parent and infill wells into several linear flow zones. In this way, three important issues can be further handled very naturally, including fracture connection between the parent and infill wells, different SRV properties for zones with different distances to the wellbore, and different production times for adjacent wellbores. The approximate expressions for different flow regimes are used in making production predictions in the time domain, and a flowing material balance method and a simple iteration are used to update the model parameters step by step. The proposed model is shown to be reasonable and accurate for handling multiwell interference problems after comparing with the commercial numerical simulator tNavigator. The synthetical cases show that the fracture parameters, SRV properties, and well infill time have a significant influence on the production performance of both the parent and infill wells. The results show that the production of the parent well will be dramatically enhanced when it is connected with the infill well via high-conductive hydraulic fractures. Longer unconnected fractures and more fracturing stages/clusters for the infill well will result in higher production for the infill well, but a negative effect is observed for the parent well. The permeability of the distant well SRV has a similar influence on the parent and infill wells. The results also show that late time well interference will result in a more significant increase in production rate on the log-log plots for the severe depletion around the parent well. Finally, the proposed model is used to analyze the production data of a field case from Fuling shale in Southwestern China. After analyzing the production data, several parameters can be obtained for both parent and infill wells, including the fracture lengths and conductivities, numbers of connected fractures, and the near and distant well permeabilities of the SRV. This gives a basic and practical technique for production prediction, formation and fracture evaluation, and well connectivity analysis from shale gas wells with fracture connection.

show abstract

Section: Introductionmentioning

confidence: 99%

A Semianalytical Model for Analyzing the Infill Well-Caused Fracture Interference from Shale Gas Reservoirs

Fang

Dai

et al. 2021

Geofluids

View full text Add to dashboard Cite

show abstract

History-Matching and Forecasting a Tight Rich-Gas Condensate Reservoir in Middle East using an Integrated Numerical and Analytical Workflow Based on Rate Transient Analysis RTA

Ataei

Shofi

Kweh

et al. 2020

SPE Asia Pacific Oil &Amp; Gas Conference and Exhibition

View full text Add to dashboard Cite

Lack of long-term production data is one of the major challenges when performing analysis for tight gas reservoirs during appraisal phase. For low-permeability liquid-rich gas and gas condensate reservoirs, fracture performance will be severely affected by condensate banking as soon as dew point pressure is reached in the vicinity of the wellbore. This makes the evaluation of fracture effectiveness and potential connected volume more challenging. Although numerical simulation can account for complex PVT, reservoir and fracture characteristics and by far the most rigorous method for forecasting, it cannot be applied to all wells due to lack of analysis time and supporting data. Therefore, a more robust methodology is required to analyze production data for a limited test period during the development phase. This paper entails an efficient and robust methodology that was applied to over 80 wells in less than a few weeks for performance evaluation, history matching and forecasting. The field in this study is a layered tight gas reservoir in the Middle East, which is currently undergoing development after an extensive appraisal plan. Most of the wells are single staged vertically fracced with their performance being significantly in comparison due to the hydraulic fracturing performance, rock quality, gas richness and operating conditions. With over 100 wells planned to be drilled in this field, it is vital to analyze the existing well performances and establish a workflow emphasizing on the near wellbore region for a robust forecasting methodology for this tight liquid-rich reservoir.

show abstract

Late Time Response Analysis in Pressure Build Up Tests: Challenges and Solutions

Motaei

Ali

Rozali

2023

Day 2 Tue, March 14, 2023

View full text Add to dashboard Cite

One of the most important features that impacts the facility size and production rate commitment is the minimum connected volume which can be explored through pressure Build Up and any misinterpretation, costs the operators significantly. This paper aims to address the challenges in Late Time Response analysis of pressure Build up well tests that exploits the reservoir boundary. Knowing that the well test response at late time shows the fingerprint of multiple features such as aquifer, sand discontinuity, baffles, faults, boundaries, etc., it will be challenging to quantify the extends of the reservoir using convolved late response. Two main numerical models were built for oil and gas reservoirs in an elongated reservoir to study the lateral boundary features such as closed boundary and aquifer and understand the effect of these features on late time response to get a clearer response. Using two models, the impact of mobility contrast between the hydrocarbon, boundary distance, aquifer strength, boundary movement and structure complexity was simulated. The major finding of this paper is that a unit slope straight line can be seen in buildup test which doesn't fit any classical and analytical model for pressure build up as the expectation is to have negative slope and down-ward hump for build up response of closed boundary and aquifer. However, this can be explained through mobility reduction from hydrocarbon (oil/gas) to water. The simulation time (build up test duration) was extended to see the long-term impact theoretically and at the end the same expectation was confirmed by simulation. After radial flow, channel flow (half slope) and then unit slope (mobility reduction) and then at last the drop in the derivative response is observed. However, the drop as signature of aquifer or limited volume happened beyond practical test duration (> 1000 hours). The work highlights the true workflow to identify the true response from reservoir and have reliable reservoir characterization and shows the case studies that address the cost on 1) misinterpretation of late time response and 2) excluding the well test from analysis due to its complexity to highlight the value and criticality of the integrated analysis.

show abstract

Production Analysis PA and Application of Rate Transient Analysis RTA in Carbonate Oil Reservoirs for Reservoir Characterization and Connectivity

Cited by 3 publications

References 9 publications

A Semianalytical Model for Analyzing the Infill Well-Caused Fracture Interference from Shale Gas Reservoirs

A Semianalytical Model for Analyzing the Infill Well-Caused Fracture Interference from Shale Gas Reservoirs

History-Matching and Forecasting a Tight Rich-Gas Condensate Reservoir in Middle East using an Integrated Numerical and Analytical Workflow Based on Rate Transient Analysis RTA

Late Time Response Analysis in Pressure Build Up Tests: Challenges and Solutions

Contact Info

Product

Resources

About