CRUDE OIL DATA BANK AND ITS UTILIZATION THROUGH COMPUTERISATION

Transcription

1 Workshop on Challenges in Crude Evaluation with Changing Crude Scenario CRUDE OIL DATA BANK AND ITS UTILIZATION THROUGH COMPUTERISATION A.K. Saxena, V.S. Kukreti and M.L. Sagu Indian Institute of Petroleum, Dehradun ABSTRACT Fast and easy retrieval of theproperties of different indigenous and imported crudes and petroleum cuts is essential for a variety of applications. Towards this end, a user-friendly computer software called "CRUBNK' is being developed. The various aspects of this software like thepetroleum crudes and cuts for which the assay information can beretrieved are listed in this paper. In addition, the salient features of CRUBNK like addition of new data, complete property retrieval of any crude / cut, comparison of any / all properties for a chosen set of crudes / cuts and the retrieval of crudes / cuts having a given range of property values are described. INTRODUCTION Petroleum refining industry constitutes the largest share to chemical industry world over and is perhaps the only processing industry in which the set of raw material characteristics are not associated with its name. The characteristics of crudes oils and its cuts are not only different for different c;rudes but also change with time for the crude from the same source. The knowledge of the raw material characteristic is essential for the design of new units, exploit available hardware to the best possible extent using advanced control techniques, and the production planning to meet varying consumption pattern on the national level. Petroleum sector being the largest, the impact of all these activities on national economyis extremely significant. Therefore, evaluation of crude oils and its cuts is very essential and challenging task particularly in view of the changing crude scenario. The available data base for crude assays can be best exploited if these are 233

2 properly compiled and easily accessible in an user friendly environment. Thanks to now available data base management systems on computer, which has made this task extremely simple and effective. In this presentatioin. we plan to demonstrate how useful these computerized data banks can be for various applications. Development of such data banks for indigenous and imported crudes at lip and its 'salient features are mentioned. TYPICAL DATA BANK AND ITS USE Any comprehensive assay should provide following information. 1. Product distribution such as.light hydrocarbons Light distillates Middle distillates Heavy distillates Heavy gas oils Asphalts Residual fuel oil 2. Crude properties Sulfur content Nitrogen content Salt content Flow properties Naphthenic acids Ash content 3. True boiling point distillation Properties of narrow fractions Properties of wide boiling range fractions API as function of mid boiling point Distillate mid percent vs sulfur and pourpoint Distillate mid percent vs smoke point, octane and cetane number Distillate mid percent vs viscosity, 234

3 4. Gasoline, Naphtha, Kerosene and jet fuel Yield vs TBP cut point, API gravity, and octane number. Hydrocarbon analysis of light fraction of naphtha ASTM distillation, API gravity, flash point, smoke point of kerosene ASTM grades of aviation turbine fuel 5. Light and heavy gas oils Diesel ASTM specifications, sulfur, viscosity, aniline point, pour point, cetane number and API gravity Lube oil stock Viscosity, viscosity index, pour point flash poii!t, carbon residue, anilie point, sulfur, API gravity, characterization factor 6. Asphalt API gravity, penetratio\n, viscosity, flash point, sulfur, carbon residue, softening point, ductility. 7. Residual fuels.. Yield of residue vs gravity, sulfur, carbon residue, insoluble in normal pentane and pour point Yield of residue vs Saybolt viscosity Yield of residue vs Kinematic viscosity From this long list of crude oil characteristics it is quite evident that generation of such information for different crudes is not only challenging task, but its compilation and retrieval of information to view it for different objectives is also equally important. This. task is further complicated by the variation in these properties from time to time. This requires the repeated regeneration ofcrude assay at different interval of time and easy updation of crude data bank with revised properties. Therefore key requirement of a crude data base can be summarized as: Comprehensiveness of the data bank. Retrieval of the information for different purposes. Facility to compare properties of different crudes for good decision making Facility for conditional retrieval of properties 235

4 Easy updation of data bank in case new information is available. User friendliness. To meet these objectives we at lip are working to develop such data base. This activity as such is not new for us. In past lip has compiled crude assays in the form of well indexed reports and in worksheet environment. In the present exercise we are further exploiting state of the art tools to meet the above mentioned key requirements. CROONK- The user friendly data base for crude oils. CRUBNK has been designed as two separate data bases, one for indigenous crudes and other one for imported crudes. This division is basically due to different formats in which the crude assays are available. Development of data base of indigenous crudes is already complete while for imported crudes it is in advanced stage of development. In case ofindigenous crude data base 33 crudes are compiled which are currently available in different region. For imported crudes, data is being compiled which are currently being imported. The list of the Indian crudes covered in the data bank is presented in Table-I. Salient feature of the CRUBNK are Entry mode(for introduction of new crudes) Retrieval mode a. Property Retrieval (Complete assay of crude oil and its cuts) b. Comparison retrieval (Comparison ofcrude oils and its cuts maximum c. d. 5 at a time) Special retrieval (Comparison of individual cuts for a given crude) Conditional. retrieval (Fixing the value ofthe property, crude meeting the specification as an output) Hard copy of all the desired information. User-friendliness-(U ser, even with least experience ofcomputer can interact with CRUBNK) 236

5 Property of following heads are available. 1. CRUDE OIL NAPHTHA CUTS GAS OIL CUTS HIGH VACUUM TBP CUTS SHORT RESIDUE TBP CUTS KEROSENE CUTS LONG RESIDUE VACUUM GAS OIL Cuts are as follows Crude oil(as such) TBP cuts( 25 deg cuts from IBP to 370 C) Naphtha cutsobp-70,70-90,90-110, ,ibp-140 C) Kerosene cuts ( , , C) Gas oil ( , , C) Long residue (370 deg C+) High vacuum TBP cuts (25 deg cuts from 370 to 530/550 C) Vacuum gas oil ( , C) Short residue ( , C) CONCLUSION The advantage of the present database over the earlier one developed in lip are (i) faster retrieval (ii) comparative studies of different crudes and theirs cuts and (iii) conditional retrieval facilities. To make the presentation of the software more effective, work has been started to present the data in graphical form. This software can be very useful in future for developing correlations and properties predictions of different cuts. 2:i7

6 TABLE -1 LIST OF INDIAN CRUDE Bombay Off Shore Western Region Easter Region Godavari Basin Cauvery Basin Bombay High Heera Ratna Panna Neelam Mukta 7. N-Gujarat Mix (loc) 8. N-Kadi 9. Jotana 10. Sanand 11. Kathana 12. Viraj 13. Navagam 14. Kalol 15. Jhalora 16. Sobhashan 17. Santhol 18. Ankelashwar 19. N-G Mix(OIDB) 20. Gandhar-Ankleshwar Naharkotiya Lakwa Rudrasagar Geliki 25. Jorajan- 26. Kharsang 27. AssamMix 28. Badarpur 29. Ravva Ravva Palk Strait 32. Kovil - Kallapam 33. Narimanam 238

7 Q. Ans. Q. Ans. Q. P.V.Rao ElL, Process & Design Dept. New Delhi Dr. A~K.Saxena lip, Dehradun S.K.Srivasatava Triune Projects Chemicals Ltd. A.K.Saxena lip., Dehradun S.K.Srivastava DISCUSSION From the data base is it possible to import a particular cut data into a simulation package so that one can connect these data into a simulation software? Actually in this data base properties of different cuts are compiled but in what format it is required by simulation package that is to be specified,and once it is specified, the next option is the possibility to create an ASCII file and ASCII file can be read through the simulation package in the required format wherever it is required and software has to be telling with specific. requirement which can be done, using these ASCII file by small programme. What just you have presented is a set of crude oils from indigenous sources. Have your compiled some data on imported crudes also? Weare compiling at present but the formatting is slightly different in case of imported crudes, that is why certain pages are working on. However, all the information on imported as well indigenous crudes, in the form of compiled report is available. For the form of data base it is being compiled How many indigenous crudes you 239

8 Ans. Q. Ans. Q. Ans. Triune Project Chemicals Ltd. Delhi A.K.Saxena lip, Dehradun P.V.Rao ElL Process Design Dept. New Delhi A.K.Saxena lip, Dehradun P.V.Rao ElL, Process Design Dept. New Delhi A.K.Saxena lip, Dehradun have put in your data base? 33 Crudes which are currently available in the country. You are able to retrieve the ASTM distillation data for different cuts; Are these predetermined cuts or we can specify any cut that we want? No, these are predetermined cuts, only based on the analysis available, generated, in our crude evaluationlabora tory. I did not see any menu coming on the screen. You have shown only one naphtha cut that is 70-90oC.Are other cuts available? I have just demonstrated only one naphtha cut 70-90oC but otherwise in this data base software other cuts are also available. 240