How to get the most out of your mature Oil field

We have all been there… it’s another downturn! There is pressure from management to demonstrate that our mature oil field is profitable.

We need to take action to maximise free cash flow to ensure the profitability of our operation and that means maximising production, minimising water and sand, while making sure well integrity is preserved. On top of that we also have to deal with foaming, scaling or emulsions, while optimising the use of expensive chemicals.

In the meantime, drilling operations, well interventions and new well completions are also being executed as scheduled, and everybody (and specially management) is keen to know the wells are performing better, after such expensive services.

As Engineers, what are the processes and tools we need to effectively monitor the field’s performance and make the decisions that will impact the bottom line?

After all, we don’t want the field to be shut in… 

#1 Well Surveillance 

We need to be able to monitor real time process variable trends for every single well on production and injection: WHP, WHT, gas lift rate, downhole sensors, injection rates. You know your wells, and you know you can spot problems just by looking at the trends and focusing on any unexpected changes. However, it may also be necessary to derive some useful variables: delta-p across a choke, an inferred downhole pressure, or drawdown. We need to be able to configure these calculations on the fly and see the historical trend. 

#2 Well Production Tests 

Well tests need to be executed as scheduled and communicated to the engineering team for validation, and then compared with actual model results (if available) for well performance optimisation. A new schedule of well tests needs to be communicated to operations, with any re-tests required. If wells are comingled, calculations are required to estimate each well’s production rates.  

New wells and worked-over wells need a well test to be completed as soon as they come online to establish their productivity index and well potential. 

This process and information flow needs to be streamlined and prioritised as much as possible, to allow engineers to focus on productive analysis and decision making. 

#3 Artificial Lift Optimisation 

Gas for artificial gas lift is always a limited resource. Every SCF (or Sm3) of gas needs to be allocated to the well that will produce the more barrels of oil. This can be done with a production optimisation tool, in which case all well models need to be up to date (which will take a lot of effort), or empirically. 

In any case, close surveillance is key to verify if the production has increased as a result of any changes in allocation. ESPs need to be closely monitored for abnormal operating conditions or operating modes that can lead to failure. 

#4 Sand and Erosion Monitoring 

Sand rates need to be measured or estimated; and used in engineering tools to estimate maximum erosion rates to limit production if necessary. Production rate or drawdown limits need to be calculated, evaluated by engineers, and properly communicated to operators to maximise oil and gas production while reducing the risk due to sand production. 

#5 Chemical Injection 

The chemist will determine the optimal chemical concentration required by each well and the facility. Engineers need to ensure that each well and every single system is receiving the correct chemical flow rate to achieve such concentration; otherwise, the consequences will soon be felt in sub-optimal production. Concentration is a function of chemical flow and production flow, but very frequently the production flow can only be estimated. So, based on this estimation, the required chemical flow setpoint can be calculated and applied. 

Another important factor is controlling the inventory of chemicals. Based on estimated or measured chemical rates, the “days remaining” of each chemical can be estimated, so that new stocks can be ordered to arrive on time. Lack of anti-foaming agent can lead (and has led!) to a complete flow station shut down! 

#6 Efficient Communications 

Decisions on gas lift allocation or ESP drive speeds, choke settings, rate or drawdown limitations, chemical injection rates and the schedule of well tests to perform… all need to be effectively communicated to the operations team. But we cannot afford to waste time every week copying and pasting from Excel sheets and other applications into a unified report. Calculated data and settings need be available to be issued in a pre-configured report along with commentary about maintenance work and well integrity issues. 

Automating and facilitating all these processes will result in Engineers having more time to do what they do best: Analysis of data and decision making, which will have the greatest impact on field productivity. 

Eigen Ingenuity packs all the functionality you need to do field wide surveillance, perform calculations to extract valuable insights, and be notified of changes and our Digital Meetings is being used by Offshore oil and gas operators to issue pre-configured reports to the Operations team and Management. And all of this is accessible from anywhere on any device, even when working from home. Field surveillance is even possible on the go using our Mobile Monitor app. 

written by

Joel Chacon

posted on

May 27, 2020

you may also like...