MudSim is a tool for the drilling operator for:

Planning optimal drilling fluid for a future well to be drilled
Utilizing the planning to perform fast simulations to keep the optimal drilling fluid when in operation.

Introduction

Drilling a well using drilling fluid has many challenges and problems. Often there are unforeseen events related to use of wrong type of drilling fluid. This could be problems with unwanted environmental emissions, ineffective hole cleaning, hole instability, uncontrolled blowout, problems keeping the drilling speed and possible to monitor and control mud consumption, lost circulation and waste handling. MudSim will work with characteristics like:

Equivalent circulating density (ECD)
Rate of penetration (ROP)
Hole cleaning efficiency
Hole stability
Waste management
Mud consumption
Environmental impact
Lost circulation

Drilling fluid constitutes approx. 5% of the total drilling cost, but can cause 60 – 70% cost overrun if not selected correctly. One problem is that the characteristics listed above are interwoven and interact with each other. Improving and adjusting one characteristic will impact the performance of another, making it important to see the whole picture with all characteristics before making a decision.

A second challenge is that changes happen within a short time frame. During drilling, unforeseen situations may rise as a surprise to the operation. A problem then is lack of insight and background of selection of the existing drilling fluid, related to the need to simulate various alternatives before making a decision. MudSim is improving all the listed challenges.

Methods to plan optimal Drilling Fluid

The main reason for using MudSim is the connection to a database with historical data as drilling fluid experience from previous and ongoing drilling operations. Downloading planned wellbore and the pore pressure plot, MudSim can help you out in 3 steps for each drilling section:

Step 1

Definition of importance for the eight important characteristics. This is a digitalized process with input from the operator’s preferences, historical experience and input from physical conditions. This is a typical illustration of relative importance, where the angle shows the importance compared to other characteristics:

Step 2

The performance for each characteristic is displayed as a result of selecting a fluid family and belonging fluid parameters within acceptable limit values. Radius for the same characteristic as step 1 illustrate performance, and a typical illustration can look like this:

Step 3

Last step is a review like simulations of all characteristics. This simulation can be performed with several drilling fluid families, various types of drilling fluids and corresponding fluid and process parameters. Comparing alternative values for the characteristics, and prioritize them with alternative drilling fluids, is a simulation utilizing algorithms to suggest optimal parameters in reports and figures. This step concludes with a recommended drilling fluid. In addition, it will also enable and perform:

Planning and prepare for HSE activities

Decision to help if the drilling fluid can be from reused mud or / and need to be mixed up

Give input to overall risk analyses. Typical high important characteristics with low performance might cause high risk.

Automatic reporting

Climate account like CO₂ footprint caused by Drilling Fluid selected.

Operation Phase – Methods to update fluid and process parameters with simulations and algorithms

When in the operational phase, if new situations occur and questions are raised, updated information on drilling fluid parameter can be valuable information for performing corrective action. Then MudSim can run algorithms with the updated parameters as new operational input, and suggest new drilling fluid parameters and process parameters.

Algorithms that suggest new parameters when drilling can help out the following:

MudSim to utilize operational input like downhole measurements, topside measurements, drilling parameters, mud control system, process equipment, fluid composition and mud engineer data.

Receiving data from Drilling Fluid System sensors

Calculate new parameters with algorithms

Help out towards autonomous operation.

Communicate with the Mud Control System (MCS) on the drilling rig with updated data for fluid parameters and process parameters. The MCS can then perform automatic adjustment and regulations within the mud mixin system according to the “new set point”coming from MudSim.

All listed corrective actions above are calculated with said alorithmes and consequenses for the change for all the eight characteristics are illustrated. This makes it possible to evaluate if the change have other perhaps negative unwanted influence elsewhere.