Shallow Clastics

Geological Assessment

Identify the source rocks and reservoir rocks involved in the project. For Shallow Clastics, these are often sedimentary rocks such as sandstones, siltstones, and mudstones. For example, in the Claiborne Group, primary reservoir sands include the Queen City Sand, Cook Mountain Formation, Sparta Sand, Yegua Formation, and the laterally equivalent Cockfield Formation.
Assess the quality of the source rocks, including their organic content, thermal maturity, and hydrocarbon generation potential. This can involve geochemical analysis, such as total organic carbon (TOC) content, hydrogen index (HI), and Tmax values.

Characterize the reservoir rocks in terms of their porosity, permeability, thickness, and lithological variations. For Shallow Clastics, it is crucial to identify intervals with high porosity and permeability.
Determine the spatial distribution and heterogeneity of the reservoir. This includes understanding the structural setting, such as fault systems and stratigraphic traps, which can influence hydrocarbon migration and accumulation.

Identify the "sweet spots" within the reservoir, which are areas with optimal rock properties for hydrocarbon production. These areas typically have porosity greater than 5%, oil saturation greater than 45%, and favorable conditions for industrial oil flow.

The production profile of an oil field typically includes several phases: a buildup period, a plateau period, and a decline period. You need to define the rates and durations of these phases based on the reservoir characteristics and development plan.

Determine the number and types of wells required, including producers, injectors, and any workover schedules. This involves modeling different well recoveries and scheduling the drilling of these wells to fit the field production profile.
Use tools or software to generate a field production profile by specifying well types, drilling schedules, and recoverable reserves. This helps in calculating the required number of development wells and their timing.

Develop and evaluate prediction models for the shale oil production profile. This can involve using artificial neural networks (ANN) or other advanced algorithms. The process includes data preprocessing, variable importance analysis, and assessing source-reservoir assemblages.

Prepare a detailed development plan that includes the project scope, investment decisions, and risk assessments. This plan should define the project boundaries and the basis for investment decisions.

Evaluate the range of uncertainty in the petroleum quantities forecasted to be produced. This involves considering different confidence bands and associated expected monetary values (EMVs).
Assess the commercial viability of the project, including the chance of commerciality and the range of uncertainty in the production estimates.

Classify the petroleum resources according to the Petroleum Resources Management System (PRMS) guidelines. This includes categorizing resources as Proved, Probable, Possible, and Contingent Resources, and understanding the associated uncertainties.

Project Name: Shallow Clastics Oil Project
Location: [Specify the location, e.g., Texas Coastal Plain]
Geological Setting: [Describe the structural setting, stratigraphy, and depositional systems]

Source Rocks: Organic-rich shaley facies of the Wilcox Group or similar formations.
Reservoir Rocks: Sandstones such as Queen City Sand, Cook Mountain Formation, etc.
Reservoir Characteristics: Porosity > 5%, permeability, thickness, and lithological variations.
Sweet Spots: Areas with high porosity and oil saturation, e.g., the upper and lower sweet spots in the Lucaogou Formation.

Buildup Period: Define the rate and duration based on well drilling and completion schedules.
Plateau Period: Estimate the stable production rate and duration based on reservoir performance.
Decline Period: Model the decline rate and duration considering reservoir depletion and well performance.

Well Types: Producers, injectors, and workover schedules.
Drilling Schedule: Schedule wells to match the production profile, including timing and frequency of workovers.

Uncertainty Analysis: Evaluate different confidence bands and associated EMVs.
Commercial Viability: Assess the chance of commerciality and the range of uncertainty in production estimates.

Proved, Probable, Possible Resources: Classify resources according to PRMS guidelines.
Contingent Resources: Identify resources that are dependent on the successful outcome of a pilot project or other conditions.