# PREDICTION OF THE DEW-POINT PRESSURE OF A GAS CONDENSATE RESERVOIR.

CHAT ON WHATSAPP (+234) 0803-766-4978

PREDICTION OF THE DEW-POINT PRESSURE OF A GAS CONDENSATE RESERVOIR.

CHAPTER ONE

INTRODUCTION

1.1      Background of the study

Gas Condensate Reservoir is a reservoir having a low-density mixture of liquid hydrocarbons that are present as gaseous components in the subsurface (in the reservoir). It is important to recognize that some gas condensate reservoirs show condensate dropping out within reservoirs, as well as condensate production at the surface due to pressure falling below the dew-point during production. This condensate accumulation in the reservoir initially remains immobile due to interfacial forces between it and connate water within the pores of the formation until its saturation level reaches a threshold value and becomes mobile.

Initially, the gas condensate is totally gas in the reservoir. As reservoir pressure decreases, the gas condensate exhibits a dew-point. The dew-point of a gas condensate fluid occurs when a gas mixture containing heavy hydrocarbon is depressurized until liquid is formed, that is, a substantial amount of gas-phase exists in equilibrium with an infinitesimal amount of liquid phase. Pressure is reduced; liquid condenses from the gas to form free liquid in the reservoir. Normally, there is no effective permeability to this liquid phase and it is not produced. If the pressure continues to decrease, a second dew-point will be reached and the liquid can be re-vaporized. This lower dew-point pressure is usually well below the reservoir abandonment pressure; thus it would be of no interest in reservoir performance.

By definition, dew-point pressure is simply the pressure at which an infinitesimal amount of liquid is in equilibrium with a large quantity of gas. the pressure below which liquid condense out of the gaseous phase.

A phase behaviour can be defined as the characteristics (changes in phase) exhibited by the gas when subjected to different temperature-pressure conditions.

During production, the hydrocarbon molecules undergo various phase and some property change, altering intermediate stages which are crucial in designing and operating the processes efficiently and optimally.

Unlike a pure substance that has both bubble-point and dew-point the same at a particular temperature and pressure, a gas condensate reservoir is a multi-component system thus at a particular temperature and pressure, each component present, exhibit their different characteristics. This is because the natural gas reservoir is not an ideal mixture. This can be seen clearly in fig 1.1.

Figure 1.1, Phase behaviour of Gas condensate reservoir by Li Fan, College Station, Texas, USA.

1.2       Problem statement

Condensate liquid saturation usually builds up near a wellbore area because of drawdown below the dew-point pressure, ultimately restricting the flow of gas. The near-well choking can reduce the productivity of a well by a factor of two or more. The phenomenon called condensate blockage or condensate banking results from a combination of factors, including fluid phase properties, formation flow characteristics and pressures in the formation and in the wellbore. If these factors are not understood at the beginning of field development, sooner or later production performance can suffer. This condensate blockage is a major challenge in the oil and gas sector since the production rate is reduced. Therefore, the dew-point pressure at which this formation occurs needs to be accurately predicted in order to reduce reservoir damage caused by condensate blockage and thus increase the production rate.

1.3       Aim and objectives

1.31    Aim

To improve the prediction of the dew-point pressure of a gas condensate reservoir.

1.32    Objectives

Generation of gas condensate data Generation of a new mathematical correlation to accurately predicted dew-point pressure

1.4       Significance of work

Every day, the petroleum industries are producing fluid from the condensate reservoirs in order to satisfy human and industrial needs. It is of great concern on the path of production and reservoir engineers to make sure the dew-point pressure of a gas condensate reservoir is accurately known.

As described earlier, the condensate reservoirs when produced below dew-point pressure tends to release liquid which reduces formation permeability and thus reduce production rate.

For example, well productivity in the Arun field, in North Sumatra, Indonesia, declined significantly about 10 years after production began. Well studies, including pressure transient testing, indicated the loss was caused by the accumulation of condensate near the wellbore.

Therefore, this article focuses on the prediction of the dew-point pressure of a gas condensate reservoir so that production and reservoir engineers can be aware and produce gas condensate reservoirs optimally.

1.5       Scope of work

The scope of this project is limited to developing a mathematical correlation that would be used to accurately predict the dew-point pressure of a gas condensate reservoir using data from the literature.

CONCLUSION

The ‘accurate’ prediction of dew-point pressure for gas condensate reservoirs is very important to maintain the reservoir pressure close to the dew-point ensuring maximum gas production and minimum condensate blockage. For this reason, a new correlation has been developed to predict dew-point pressure for retrograded gas condensate reservoirs. The new model is developed from a large data bank that is comprised of a larger range of pressures, temperatures, and various gas condensate compositions. The new empirical correlation has the following features:

1.Validity of the model has been studied using measured data. The new model shows acceptable agreement between forecasted dew-point pressure values and the measured ones.

2.Precision of the correlation is compared to previously published correlations. The newly proposed performed better than all published correlations. It has the highest correlation coefficient and the lowest errors (AARE and RMSE).

3.The Proposed dew-point pressure correlation is simple, easy to apply and accurate for condensate gas production schemes.

4.The new model can be used for further correlation development due to its simplicity and also predict the dew-point pressure for retrograde gas condensate reservoirs when the measured one is unavailable.

NOMENCLATURE

ARE            average relative error

AARE            average absolute relative error

R            coefficient of correlation

RMSE            root mean square error

.

## PREDICTION OF THE DEW-POINT PRESSURE OF A GAS CONDENSATE RESERVOIR.

OR CHAT ON WHATSAPP (+234) 0803-766-4978

TYPE IN YOUR TOPIC AND CLICK SEARCH.

###### RESEARCHWAP.ORG
Researchwap.org is an online repository for free project topics and research materials, articles and custom writing of research works. We’re an online resource centre that provides a vast database for students to access numerous research project topics and materials. Researchwap.org guides and assist Postgraduate, Undergraduate and Final Year Students with well researched and quality project topics, topic ideas, research guides and project materials. We’re reliable and trustworthy, and we really understand what is called “time factor”, that is why we’ve simplified the process so that students can get their research projects ready on time. Our platform provides more educational services, such as hiring a writer, research analysis, and software for computer science research and we also seriously adhere to a timely delivery.

### TESTIMONIES FROM OUR CLIENTS

Please feel free to carefully review some written and captured responses from our satisfied clients.

• "Exceptionally outstanding. Highly recommend for all who wish to have effective and excellent project defence. Easily Accessable, Affordable, Effective and effective."

Debby Henry George, Massachusetts Institute of Technology (MIT), Cambridge, USA.
• "I saw this website on facebook page and I did not even bother since I was in a hurry to complete my project. But I am totally amazed that when I visited the website and saw the topic I was looking for and I decided to give a try and now I have received it within an hour after ordering the material. Am grateful guys!"

Hilary Yusuf, United States International University Africa, Nairobi, Kenya.
• "Researchwap.org is a website I recommend to all student and researchers within and outside the country. The web owners are doing great job and I appreciate them for that. Once again, thank you very much "researchwap.org" and God bless you and your business! ."

Debby Henry George, Massachusetts Institute of Technology (MIT), Cambridge, USA.
• "Great User Experience, Nice flows and Superb functionalities.The app is indeed a great tech innovation for greasing the wheels of final year, research and other pedagogical related project works. A trial would definitely convince you."

Lamilare Valentine, Kwame Nkrumah University, Kumasi, Ghana.
• "I love what you guys are doing, your material guided me well through my research. Thank you for helping me achieve academic success."

Sampson, University of Nigeria, Nsukka.
• "researchwap.com is God-sent! I got good grades in my seminar and project with the help of your service, thank you soooooo much."

Cynthia, Akwa Ibom State University .
• "Sorry, it was in my spam folder all along, I should have looked it up properly first. Please keep up the good work, your team is quite commited. Am grateful...I will certainly refer my friends too."

Elizabeth, Obafemi Awolowo University
• "Am happy the defense went well, thanks to your articles. I may not be able to express how grateful I am for all your assistance, but on my honour, I owe you guys a good number of referrals. Thank you once again."

Ali Olanrewaju, Lagos State University.
• "My Dear Researchwap, initially I never believed one can actually do honest business transactions with Nigerians online until i stumbled into your website. You have broken a new legacy of record as far as am concerned. Keep up the good work!"

Willie Ekereobong, University of Port Harcourt.
• "WOW, SO IT'S TRUE??!! I can't believe I got this quality work for just 3k...I thought it was scam ooo. I wouldn't mind if it goes for over 5k, its worth it. Thank you!"

Theressa, Igbinedion University.
• "I did not see my project topic on your website so I decided to call your customer care number, the attention I got was epic! I got help from the beginning to the end of my project in just 3 days, they even taught me how to defend my project and I got a 'B' at the end. Thank you so much researchwap.com, infact, I owe my graduating well today to you guys...."

Joseph, Abia state Polytechnic.
• "My friend told me about ResearchWap website, I doubted her until I saw her receive her full project in less than 15 miniutes, I tried mine too and got it same, right now, am telling everyone in my school about researchwap.com, no one has to suffer any more writing their project. Thank you for making life easy for me and my fellow students... Keep up the good work"

Christiana, Landmark University .
• "I wish I knew you guys when I wrote my first degree project, it took so much time and effort then. Now, with just a click of a button, I got my complete project in less than 15 minutes. You guys are too amazing!."

Musa, Federal University of Technology Minna
• "I was scared at first when I saw your website but I decided to risk my last 3k and surprisingly I got my complete project in my email box instantly. This is so nice!!!."

Ali Obafemi, Ibrahim Badamasi Babangida University, Niger State.
• To contribute to our success story, send us a feedback or please kindly call 2348037664978.
Then your comment and contact will be published here also with your consent.

Thank you for choosing researchwap.com.