Integration of 4D Seismic Data for Improved Reservoir Management and Development Decisions in the Dan Field

Abstract The aim of the study was to create an ensemble of equiprobable models that could be used for improving the reservoir management of the Vilje field. Qualitative and quantitative workflows were developed to systematically and efficiently screen, analyze and history match an ensemble of reservoir simulation models to production and 4D seismic data. The goal of developing the workflows is to increase the utilization of data from 4D seismic surveys for reservoir characterization. The qualitative and quantitative workflows are presented, describing their benefits and challenges. The data conditioning produced a set of history matched reservoir models which could be used in the field development decision making process. The proposed workflows allowed for identification of outlying prior and posterior models based on key features where observed data was not covered by the synthetic 4D seismic realizations. As a result, suggestions for a more robust parameterization of the ensemble were made to improve data coverage. The existing history matching workflow efficiently integrated with the quantitative 4D seismic history matching workflow allowing for the conditioning of the reservoir models to production and 4D data. Thus, the predictability of the models was improved. This paper proposes a systematic and efficient workflow using ensemble-based methods to simultaneously screen, analyze and history match production and 4D seismic data. The proposed workflow improves the usability of 4D seismic data for reservoir characterization, and in turn, for the reservoir management and the decision-making processes.

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Machine learning to reduce cycle time for time-lapse seismic data assimilation into reservoir management

Interpretation ◽

10.1190/int-2018-0206.1 ◽

2019 ◽

Vol 7 (3) ◽

pp. SE123-SE130

Author(s):

Yang Xue ◽

Mariela Araujo ◽

Jorge Lopez ◽

Kanglin Wang ◽

Gautam Kumar

Keyword(s):

Machine Learning ◽

Data Assimilation ◽

Seismic Data ◽

Reservoir Management ◽

Time Lapse ◽

Water Flooding ◽

Reservoir Models ◽

Reservoir Property ◽

Property Changes ◽

4D Seismic

Time-lapse (4D) seismic is widely deployed in offshore operations to monitor improved oil recovery methods including water flooding, yet its value for enhanced well and reservoir management is not fully realized due to the long cycle times required for quantitative 4D seismic data assimilation into dynamic reservoir models. To shorten the cycle, we have designed a simple inversion workflow to estimate reservoir property changes directly from 4D attribute maps using machine-learning (ML) methods. We generated tens of thousands of training samples by Monte Carlo sampling from the rock-physics model within reasonable ranges of the relevant parameters. Then, we applied ML methods to build the relationship between the reservoir property changes and the 4D attributes, and we used the learnings to estimate the reservoir property changes given the 4D attribute maps. The estimated reservoir property changes (e.g., water saturation changes) can be used to analyze injection efficiency, update dynamic reservoir models, and support reservoir management decisions. We can reduce the turnaround time from months to days, allowing early engagements with reservoir engineers to enhance integration. This accelerated data assimilation removes a deterrent for the acquisition of frequent 4D surveys.

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Use of Quantitative 4D-Seismic Data in Automatic History Match

10.2118/94650-ms ◽

2005 ◽

Cited By ~ 3

Author(s):

Ricardo Cunha Mattos Portella ◽

Alexandre Anoze Emerick

Keyword(s):

Seismic Data ◽

History Match ◽

4D Seismic

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A Physics-Based Loss Function to Constrain Neural Network Inversion of 4D Seismic Data

10.3997/2214-4609.202112968 ◽

2021 ◽

Author(s):

G. Corte ◽

C. MacBeth

Keyword(s):

Neural Network ◽

Loss Function ◽

Seismic Data ◽

Neural Network Inversion ◽

4D Seismic

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A Bayesian Approach for Resolving OWC and GOC from 4D Seismic Data

10.3997/2214-4609.202037002 ◽

2020 ◽

Author(s):

H. Amini ◽

C. MacBeth

Keyword(s):

Bayesian Approach ◽

Seismic Data ◽

4D Seismic

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Time-Lapse Seismic for Reservoir Management: Case Studies From Offshore Niger Delta, Nigeria

SPE Reservoir Evaluation & Engineering ◽

10.2118/170808-pa ◽

2016 ◽

Vol 19 (03) ◽

pp. 391-402

Author(s):

Sunday Amoyedo ◽

Emmanuel Ekut ◽

Rasaki Salami ◽

Liliana Goncalves-Ferreira ◽

Pascal Desegaulx

Keyword(s):

Case Studies ◽

Niger Delta ◽

Reservoir Management ◽

Time Lapse ◽

Seismic Survey ◽

Elastic Model ◽

Field Development ◽

4D Seismic ◽

The Impact

Summary This paper presents case studies focused on the interpretation and integration of seismic reservoir monitoring from several fields in conventional offshore and deepwater Niger Delta. The fields are characterized by different geological settings and development-maturity stages. We show different applications varying from qualitative to quantitative use of time-lapse (4D) seismic information. In the first case study, which is in shallow water, the field has specific reservoir-development challenges, simple geology, and is in phased development. On this field, 4D seismic, which was acquired several years ago, is characterized by poor seismic repeatability. Nevertheless, we show that because of improvements from seismic reprocessing, 4D seismic makes qualitative contributions to the ongoing field development. In the second case study, the field is characterized by complex geological settings. The 4D seismic is affected by overburden with strong lateral variations in velocity and steeply dipping structure (up to 40°). Prestack-depth-imaging (PSDM) 4D seismic is used in a more-qualitative manner to monitor gas injection, validate the geologic/reservoir models, optimize infill injector placement, and consequently, enhance field-development economics. The third case study presents a deep offshore field characterized by a complex depositional system for some reservoirs. In this example, good 4D-seismic repeatability (sum of source- and receiver-placement differences between surveys, dS+dR) is achieved, leading to an increased quantitative use of 4D monitoring for the assessment of sand/sand communication, mapping of oil/water (OWC) front, pressure evolution, and dynamic calibration of petro-elastic model (PEM), and also as a seismic-based production-logging tool. In addition, 4D seismic is used to update seismic interpretation, provide a better understanding of internal architecture of the reservoirs units, and, thereby, yield a more-robust reservoir model. The 4D seismic in this field is a key tool for field-development optimization and reservoir management. The last case study illustrates the need for seismic-feasibility studies to detect 4D responses related to production. In addition to assessing the impact of the field environment on the 4D- seismic signal, these studies also help in choosing the optimum seismic-survey type, design, and acquisition parameters. These studies would possibly lead to the adoption of new technologies such as broad-band streamer or nodes acquisition in the near future.

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Time-Lapse Seismic Monitoring of Onshore Reservoirs in Niger Delta, Field ‘K’ as a Case Study

Nigerian Journal of Environmental Sciences and Technology - March 2018 ◽

10.36263/nijest.2017.01.0010 ◽

2017 ◽

Vol 1 (1) ◽

pp. 23-27 ◽

Cited By ~ 1

Author(s):

A. Ogbamikhumi ◽

T. Tralagba ◽

E. E. Osagiede

Keyword(s):

Seismic Data ◽

Acoustic Impedance ◽

Niger Delta ◽

Rock Physics ◽

Time Lapse ◽

Seismic Survey ◽

Impedance Change ◽

Data Set ◽

Reservoir Fluid ◽

4D Seismic

Field ‘K’ is a mature field in the coastal swamp onshore Niger delta, which has been producing since 1960. As a huge producing field with some potential for further sustainable production, field monitoring is therefore important in the identification of areas of unproduced hydrocarbon. This can be achieved by comparing production data with the corresponding changes in acoustic impedance observed in the maps generated from base survey (initial 3D seismic) and monitor seismic survey (4D seismic) across the field. This will enable the 4D seismic data set to be used for mapping reservoir details such as advancing water front and un-swept zones. The availability of good quality onshore time-lapse seismic data for Field ‘K’ acquired in 1987 and 2002 provided the opportunity to evaluate the effect of changes in reservoir fluid saturations on time-lapse amplitudes. Rock physics modelling and fluid substitution studies on well logs were carried out, and acoustic impedance change in the reservoir was estimated to be in the range of 0.25% to about 8%. Changes in reservoir fluid saturations were confirmed with time-lapse amplitudes within the crest area of the reservoir structure where reservoir porosity is 0.25%. In this paper, we demonstrated the use of repeat Seismic to delineate swept zones and areas hit with water override in a producing onshore reservoir.

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