DWIS Service: Downhole ECD

This repository contains a .NET-based DWIS solution for real-time computation of Downhole Equivalent Circulation Density (ECD) from:

• downhole annulus pressure
• bottom-of-string depth
• well trajectory
• wellbore architecture
• BHA/drill string context

The computational definition is aligned with SPE-217668-MS: https://doi.org/10.2118/217668-MS.

Solution Overview

This is a multi-project solution built around a DWIS blackboard data exchange pattern:

1. A data source publishes realtime input signals.
2. A server service subscribes to inputs and contextual data, computes ECD, and publishes outputs.
3. A data sink subscribes to outputs for validation/monitoring.

The solution also includes a shared-model generator used to produce contextual DTOs and merged schema artifacts.

Project Structure

• DWIS.Service.DownholeECD.Model
  • Domain and semantic data contracts for realtime inputs/outputs and contextual data.
  • Includes conversion logic (DownholePressureConverter) for pressure-to-ECD processing.
• DWIS.Service.DownholeECD.Server
  • Hosted worker that runs the realtime computation loop.
  • Reads inputs and context from the blackboard, computes ECD, and publishes outputs.
• DWIS.Service.DownholeECD.DataSource
  • Helper worker that publishes synthetic realtime inputs (depth and annulus pressure).
  • Useful for testing and demonstrations without field data.
• DWIS.Service.DownholeECD.DataSink
  • Helper worker that subscribes to computed outputs and logs them.
  • Used to verify end-to-end data flow.
• DWIS.Service.DownholeECD.ModelSharedOut
  • Console utility that merges OpenAPI schema dependencies and generates shared C# DTO/client code.
  • Produces DownholeECDMergedModel.cs and DownholeECDMergedModel.json.

Data Flow

1. DataSource publishes:
   • BottomOfStringDepth
   • AnnulusPressure
2. Server subscribes to:
   • realtime inputs
   • trajectory JSON payload
   • wellbore architecture JSON payload
   • BHA/drill string JSON payload
3. Server computes and publishes:
   • DownholeEquivalentCirculationDensity
   • TopLiquidLevelReferenceTVD
   • TopLiquidLevelReferencePressure
4. DataSink subscribes to these outputs and logs values.

Prerequisites

• .NET 8 SDK
• Access to a DWIS-compatible blackboard endpoint
• Configuration for loop timing and blackboard endpoint

Default local configuration is provided in:

• home/config.json

Example values:

• LoopDuration: 00:00:01
• GeneralBlackboard: opc.tcp://localhost:48030

Build

From repository root:

dotnet restore
dotnet build DWIS.Service.DownholeECD.sln

Run (Local End-to-End)

Start services in separate terminals from repository root:

dotnet run --project DWIS.Service.DownholeECD.Server

dotnet run --project DWIS.Service.DownholeECD.DataSource

dotnet run --project DWIS.Service.DownholeECD.DataSink

Recommended startup order:

1. Server
2. DataSource
3. DataSink

Shared Model Generation

To regenerate shared contextual DTOs and merged OpenAPI schema:

dotnet run --project DWIS.Service.DownholeECD.ModelSharedOut

Inputs:

• DWIS.Service.DownholeECD.ModelSharedOut/json-schemas/*.json

Generated outputs:

• DWIS.Service.DownholeECD.ModelSharedOut/DownholeECDMergedModel.cs
• DWIS.Service.DownholeECD.Service/wwwroot/json-schema/DownholeECDMergedModel.json

Notes

• DataSource and DataSink are helper applications for integration/testing workflows.
• The core runtime service is DWIS.Service.DownholeECD.Server, using contracts and logic from DWIS.Service.DownholeECD.Model.