SPE Workshop: Gas Well Deliquification 9 - 10 Nov 2017 Mercure Hotel Den Haag Central The Hague, The Netherlands


Thursday, November 09

09:00 - 09:40
Keynote Speech
Speaker(s) Lucia van Geuns, TNO

Public concern over earthquake risk from the gas extraction at the Groningen Field, the Netherlands, forced the Dutch Minister of Economic Affairs into a succession of policy shifts to balance safety concerns with maintaining supplies to the country’s households. Ninety-eight percent of the population of the Netherlands is provided with gas from the Groningen gas field. All domestic appliances are configured for this type of gas. In 2013, 53.9 billion m3 of natural gas was still extracted from the Groningen reserves. In 2017, the Government decided to reduce the allowable annual production volume approved by its own Regulatory Authority to 21.6 x 109 m3. With production from the small gas field (‘kleine velden’) declining at a rate of some 7% / year and the current Groningen production cap, the EU will need to increase gas imports from other sources. The situation is furthermore compounded by the widespread public concern about global warming and the consequent climate change caused by the burning of fossil fuels. The 2015 Paris Climate Treaty (COP21) requires all signatories to reduce their CO2 emissions.

This presentation provides a brief overview of the changing role of natural gas in the Netherlands in the inevitable transition towards a sustainable economy.

09:40 - 10:30
Session 1: Liquid Loading, Water Production and Salt Precipitation – Recognition and Modelling
Session Chairpersons Ricardo Gijbels, EBN; Ewout Biezen, Shell

Liquid loading, water production and salt precipitation are some of the most common issues affecting gas wells especially close to the end of their production life. As a reservoir is depleted, the bottom-hole flowing pressure decreases, resulting in a lower production velocity in the well, which reduces gas efficiency in carrying liquids to surface. These liquids can be formation or condensed water, condensate or oil (if an oil rim is produced together with the gas). The result is the same: as liquids accumulate in the well, the backpressure on the reservoir increases, further reducing productivity and eventually leading to total loss of production. Any inflow impairment, caused for instance by salt precipitation or condensate banking, aggravates this condition and may severely impact production.

In this session, we will look at the overall picture of gas and oil fields and wells in production in the Netherlands, and their related liquid loading/water production and salt precipitation issues. In addition, we will review tools and methodologies to identify liquid loading, water production and salt precipitation.

10:30 - 11:00
11:00 - 12:30
Session 2: Field Operations and Asset Integrity
Session Chairpersons Marco Marino, NAM; Ricardo Gijbels, EBN

Many assets, especially in their tail-end production phase, often suffer from liquid loading problems, and the related mitigation measures such as (automatic) intermittent production, water shut-offs, foam injection, velocity strings or gas lift invariably have a large impact on how the wells and the asset are operated.  Increased water production, for instance, can cause process upsets and may require increased operator attention to monitor and adjust process parameters. The changed chemistry of produced water when foamers (surfactants) have been added to the produced water stream also can lead to reduced separation efficiency and potential carryover of liquids to the gas phase or increased oil in water content, if not dealt with properly.

Very often the efforts to resolve liquid loading in wells will lead to extending production life to recover additional capital or operational cost. These may take field life many years beyond the originally planned period to recover additional (preventive) maintenance cost at the very least additional inspection activities. The original completion designs of gas wells should be designed with the complete requirements from initial plateau to tail-end production in mind. Unfortunately, this is often not the case and considerable design work and modifications are needed before the wells are ready for the deliquification solution of choice. Compatibility of the original completion materials with the to-be installed liquid loading solution is key, and has to be an important consideration of the solution selection criteria.

In this session, we will review several case studies and real life examples of optimization, stimulation and artificial lift of late life wells. Furthermore we will take a look at the integrity consequences of both specific artificial lift choices and more general extension of end of field life.

12:30 - 13:30
13:30 - 14:30
Breakout Session 1: Modelling
Moderator(s) Stefan Belfroid, TNO; Ricardo Gijbels, EBN

A lot of effort is still being put in the modelling of (wet) gas well behavior. This modelling includes predicting the state of the well (loading vs. non loading), prediction of salt/scale precipitation and detailed models for the pressure drop in vertical/inclined flow. Also, efforts that include the effects of the reservoir on the dynamic behaviour of wells are getting more attention.

In this break-out session, we would like to discuss the requirements of the operators and what they consider to be the most valuable modelling. This could well be where the most uncertainty exists in the model train from the following: reservoir – inflow – tubing – (pumps/artificial lifts) – wellhead choke – separator – compressor.

Do we expect the uncertainties to be in:

  • Pressure drop-in reservoir, tubing, wellhead choke
  • Predictions of liquid (condensate/water) rates
  • Dynamic behavior
  • Prediction capabilities of operator influence such as rate of choke opening, bull heading, or wash job?


Preparation for the Breakout session
What is in the opinion of the delegate’s least reliable trajectory in the predicting of the gas production rate (if possible with field examples)?

14:30 - 15:00
15:00 - 16:30
Session 3: Data Management, Modelling and Optimisation
Session Chairpersons Stefan Belfroid, TNO; Bin Hu, Kongsberg Digital

During the end of life of a gas well a large number of different aspects play a role: liquid loading efficiency, flow instabilities in the well, liquid drainage during production and during shut-in. With deliquification methods applied, such as foamer injection, gas lift, ejectors, the detailed prediction of all these aspects becomes even more complicated and important to gauge the effectiveness of these methods. In this session, all modelling aspects of gas wells are covered. From foam film models up to real-time production optimization in case of wells suffering from salt precipitations. The goal of this session is to provide insights in the latest models and how to use them for optimization. This includes steady state models up to full near-well transient models. Additionally, the application of using historical and real-time production history matching to improve the predictions for surveillance and optimization purposes will be covered.

16:30 - 17:30
Breakout Session 2: Big Data Analytics
Moderator(s) Pejman Shoeibi Omrani, TNO; Marco Marino, Shell

In the previous SPE gas well deliquification workshop, there were discussions on the role of data-driven modelling and big data in upstream oil and gas. As a follow up, several workshops, seminars and interviews were organized together with operators to discuss the opportunities of big data analytics.

The agenda for this breakout session is:

  • Status update
    • Overview of big data developments in oil and gas
    • Summary of the TKI big data workshop and reinvented oil and gas seminar
  • Initiatives and recent developments of operators in the field of big data analytics (round table)
  • Discussion on the next steps
    • What is a suitable test case to show the added value of big data?
    • What are the challenges, barriers and show stoppers?


Preparation for the Breakout session
Delegates are encouraged to think of a test case where big data analytics could be of an added value to their operational challenges. Bring the test case to the breakout session

Friday, November 10

09:00 - 09:30
Keynote Speech
Speaker(s) Eilard Hoogerduijn-Strating, NAM

Gas meets Wind 

09:30 - 11:00
Session 4: Lessons Learned from Oil Production Well Instabilities and Oil Production Artificial Lift
Session Chairpersons Stefan Belfroid, TNO; Bin Hu, Kongsberg Digital

Multiphase phenomena like liquid back flow, loading and slugging are common in gas producing wells as well as in oil producing wells.  

In oil wells a rich experience was developed over the past decades in dealing these flow instabilities via for instance gas lift or downhole pumps. In addition to the practical methods the modelling capabilities also have a longer history. In this session the lessons learned from artificial lift in oil producing wells suitable for gas producing wells are discussed. But of course also the lessons learned in gas well deliquification suitable to improve the artificial lift in oil wells are included.

11:00 - 11:30
11:30 - 12:30
Session 5: Chemical Injection for Production Enhancement
Session Chairpersons P.S.(Pejman) Shoeibi Omrani, TNO

There has been an extensive interest in North Sea for chemical injection to mitigate mature gas wells production issues, such as liquid loading and salt precipitation. For instance, foamer injection for gas well deliquification, scale inhibitors squeeze or salt washes and acid jobs for stimulating the production. The topics related to this session are (but not limited to);

  • Fundamental studies and investigation of chemicals and multiphase flow dynamics in the (near)wellbore
  • Development and selection of suitable and effective chemicals by considering the production performance and integrity of facilities (e.g. lower corrosion rate)
  • Modelling the effect of chemical injection and predicting the production gain
  • Field stories of chemical injections
12:30 - 13:30
13:30 - 15:00
Breakout Session 3
Moderator(s) Bin Hu, Kongsberg Digital; Ewout Biezen, Shell

Over the years, the gas well deliquification developments have covered a wide range of solutions, ranging from foam injection to velocity strings, compression, pumps etc. In the application of these solutions lessons have been learned over the years by the operators applying the solutions and the service companies providing the solutions.

In this break-out session we want to come up with a comprehensive set of best practices for the most commonly used deliquification techniques. Furthermore we want to define the main skills requirements for the optimal operation of liquid loading gas wells with one (or more) of the deliquification solutions installed.


The agenda for this breakout session is:

  • Group 1: Brainstorm and define key best practices for the main deliquification techniques (foam, velocity strings, compression, other).
  • Group 2: Determine the key skills that the deliquification operator needs in order to successfully extend field life.

Plenary: Feedback group results and determine the best way forward.


Preparation for the Breakout session

Delegates are encouraged to think of their experience developing best practices for their main deliquification techniques. Also, think about the specific skills that are required to successfully operate tailend gas wells with deliquification methods installed.

15:00 - 15:30