The Workflow
Perhaps the most useful method for evaluating a future production improvement project is an evaluation of previous projects. An uplift from a previous workover would logically be applied or adapted to forecast a future workover. The problem is that it takes extensive time and effort to gather and analyze the data from previous projects. OVS has created a process called uplift analysis to automate volume changes resulting from a workover or change in operation. The results of the uplift analysis can be used to evaluate an action allowing better decisions to be made in future projects.
The Challenge
Logically, all projects large or small should be reviewed for success upon conclusion. The reality is that only large projects, like waterflood conversions, get full post mortem analysis. Small projects like pump changes, on the other hand, may be ignored because the costs were low or incremental production small. The success, however, should influence future decisions, if the analysis is available.
Uplift analysis involves the gathering and analysis of data pre-work and comparing it to the post-work results. Typically, production data is extrapolated using the pre-work trend and compared to the actual production post-work. The difference between the extrapolation and the actual is the volume of uplift. This extrapolation or Decline curve analysis is a common analysis technique throughout the industry. Why then is it a challenge to perform uplift analysis?
First, decline curve analysis (DCA) tools are used typically by reservoir engineers and may not be available or are unfamiliar to production engineers or operators.
Second, most DCA forecasts from the latest production into the future rather than from some point in history, and manual intervention is needed to perform this analysis. When a project effects a large number of wells or performed individually on numerous wells, this manual intervention will add to the analysis effort. Many times engineers will reduce this effort by aggregating the wells and reducing the granularity.
Regardless of the reason for performing the uplift analysis, it can be time consuming. In some cases, so time consuming that short-cuts are introduced or the entire process is simply skipped.
The Solution
Working with our clients, OVS Group has created an Uplift Analysis workflow to enable and, where possible, automate the process of uplift analysis. The Uplift Analysis workflow evaluates the impact of well interventions on production. The workflow allows engineers to evaluate multiple events and the effects they have had on the well production over time.
The Uplift Analysis workflow allows the user to opt for an automated workflow, where the system detects when certain events occurred and then automatically forecasts from that date forward. This automation could be performed over a large number of wells. The workflow also allows the user to target the historical event from which to analyze.
Traditionally, this type of uplift analysis would be applied to oil or gas production, however similar approaches for other key performance data can also be included.
Results of the analysis are stored based on the business rules of the client and can be used in reports or as part of a surveillance process. These results can be easily integrated with other workflows, allowing engineers to pinpoint which projects were successful and should be continued. Uplift Analysis is also easily integrated with financial data to provide an economic ranking of each well intervention.
Final Thoughts
Uplift analysis can be a powerful tool to help an organization evaluate on-going improvement efforts. The workflow is often combined with other workflows like Well Review or the Oilfield Coordination Workflow. One client uses the Oilfield Coordination workflow to indicate a specific workover to track. The uplift workflow automatically tracks the improvement project and delivers results to the engineers. This combination has significantly streamlined much of the post workover analysis performed for this company.
For more information, please contact OVS.
