Calibration of petrophysical evaluation results of clastic reservoirs using core data, in the offshore depobelt, Niger Delta, Nigeria

2021 ◽  
Author(s):  
Samuel Okechukwu Onyekuru ◽  
Julian Chukwuma Iwuagwu ◽  
Adaeze Ulasi ◽  
Ikechukwu Sabinus Ibeneme ◽  
Cyril Ukaonu ◽  
...  
Keyword(s):  
Niger Delta ◽  
Core Data ◽  
Clastic Reservoirs ◽  
Petrophysical Evaluation

Petrophysical Type Curves for Identifying the Electrical Character of Petroleum Reservoirs

2007 ◽  
Vol 10 (06) ◽  
pp. 711-729 ◽  
Author(s):  
Paul Francis Worthington
Keyword(s):  
Water Saturation ◽  
Early Stage ◽  
Well Logs ◽  
Log Analysis ◽  
Well Log ◽  
Formation Water ◽  
Water Conductivity ◽  
Core Data ◽  
Water Saturated ◽  
Petrophysical Evaluation

Summary A user-friendly type chart has been constructed as an aid to the evaluation of water saturation from well logs. It provides a basis for the inter-reservoir comparison of electrical character in terms of adherence to, or departures from, Archie conditions in the presence of significant shaliness and/or low formation-water salinity. Therefore, it constitutes an analog facility. The deliverables include reservoir classification to guide well-log analysis, a protocol for optimizing the acquisition of special core data in support of log analysis, and reservoir characterization in terms of an (analog) porosity exponent and saturation exponent. The type chart describes a continuum of electrical behavior for both water and hydrocarbon zones. This is important because some reservoir rocks can conform to Archie conditions in the fully water-saturated state, but show pronounced departures from Archie conditions in the partially water-saturated state. In this respect, the chart is an extension of earlier approaches that were restricted to the water zone. This extension is achieved by adopting a generalized geometric factor—the ratio of water conductivity to formation conductivity—regardless of the degree of hydrocarbon saturation. The type chart relates a normalized form of this geometric factor to formation-water conductivity, a "shale" conductivity term, and (irreducible) water saturation. The chart has been validated using core data from comprehensively studied reservoirs. A workflow details the application of the type chart to core and/or log data. The analog role of the chart is illustrated for reservoir units that show different levels of non-Archie effects. The application of the method should take rock types, scale effects, the degree of core sampling, and net reservoir criteria into account. The principal benefit is a reduced uncertainty in the choice of a procedure for the petrophysical evaluation of water saturation, especially at an early stage in the appraisal/development process, when adequate characterizing data may not be available. Introduction One of the ever-present problems in petrophysics is how to carry out a meaningful evaluation of well logs in situations where characterizing information from quality-assured core analysis is either unavailable or is insufficient to satisfactorily support the log interpretation. This problem is especially pertinent at an early stage in the life of a field, when reservoir data are relatively sparse. Data shortfalls could be mitigated if there was a means of identifying petrophysical analogs of reservoir character, so that the broader experience of the hydrocarbon industry could be utilized in constructing reservoir models and thence be brought to bear on current appraisal and development decisions. Here, a principal requirement calls for type charts of petrophysical character, on which data from different reservoirs can be plotted and compared, as a basis for aligning approaches to future data acquisition and interpretation. This need manifests itself strongly in the petrophysical evaluation of water saturation, a process that traditionally uses the electrical properties of a reservoir rock to deliver key building blocks for an integrated reservoir model. The solution to this problem calls for an analog facility through which the electrical character of a subject reservoir can be compared with others that have been more comprehensively studied. In this way, the degree of confidence in log-derived water saturation might be reinforced. At the limit, the log analyst needs a reference basis for recourse to capillary pressure data in cases where the well-log evaluation of water saturation turns out to be prohibitively uncertain.

Estimation of Reservoir Permeability Using Analogue Core Data for Green Field: Case Studies from Niger Delta

2019 ◽  
Author(s):  
Anindya Das ◽  
Chinedu Anijekwu ◽  
Kelly Maguire ◽  
Mark Wood ◽  
Segun Akinrolabu ◽  
...  
Keyword(s):  
Case Studies ◽  
Niger Delta ◽  
Field Case ◽  
Core Data ◽  
Reservoir Permeability

Integration of 3D Seismic in the Absence of Core Data To Mitigate Porosity Uncertainty in a Deep, Over Pressure Reservoir in Niger Delta

2014 ◽  
Author(s):  
Prahlad Basak ◽  
Abiola Abdul-Kareem ◽  
James C. Anyaehie ◽  
Muyiwa Esho
Keyword(s):  
Niger Delta ◽  
3D Seismic ◽  
Core Data

Deciphering the Impact of Subsurface Geology on Reservoir Quality Indicators: Petrophysical Evaluation from Niger Delta

2014 ◽  
Author(s):  
Okechukwu Ossai ◽  
Chiara Cavalleri ◽  
Chandramani Shrivastva ◽  
Michel Claverie
Keyword(s):  
Quality Indicators ◽  
Niger Delta ◽  
Reservoir Quality ◽  
Subsurface Geology ◽  
The Impact ◽  
Petrophysical Evaluation

scholarly journals Seismic interpretation and petrophysical evaluation of SH field, Niger Delta

2017 ◽  
Vol 8 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Oluseun Adetola Sanuade ◽  
Adesoji Olumayowa Akanji ◽  
Abayomi Adesola Olaojo ◽  
Kehinde David Oyeyemi
Keyword(s):  
Niger Delta ◽  
Seismic Interpretation ◽  
Petrophysical Evaluation
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