Report on field visit to dakhni oil field

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Report on field visit to dakhni oil field

  1. 1. REPORT ON FIELD TO DAKHNI OIL FIELD SUBMITTED BY: SABA SAIF SUBMITTED TO: MAM SAIMA AKBAR SUBMISSION DATE: 13-DEC-2012
  2. 2. FIELD TO DAKHNI OIL FIELD ACKNOWLEGMENT All praise to Allah Almighty who blessed us with the courage and ability to work on this report and to compile it. We would like to thank MamSaimaAkbar whose guidance and vast knowledge and interest helped us a lot in understanding different oil and gas exploration techniques and also helped us in the field and to get a practical knowledge about the field. 2
  3. 3. FIELD TO DAKHNI OIL FIELD TABLE OF CONTENTS Chapter #1:Introduction 1.1General statement………………………………………………………………………..…05 1.2 Location of the Field …………………………………………………………………….…05 1.3 Accessibility………………………………………………………………….………….….05 1.4 Purpose of the visit………………..…………………………………………….…………..05 Chapter # 2: Production and Precautions at the Field 2.1 Health SafetyPrecautions …………………...……………………………………….……07 2.2 Working……………………………………………………………….……………….…...08 2.3 Control and Improvements…………………………………………………………………09 3.0 Conclusion ………………………………………………………………………………....09 3
  4. 4. FIELD TO DAKHNI OIL FIELD CHAPTER # 1 INTRODUCTION 4
  5. 5. FIELD TO DAKHNI OIL FIELD 1.1GENERAL STATEMENT This report has been compiled in response to the field trip that was arranged by the Department of Earth and Environmental Sciences (E& ES) on 1st December,2012 for BS Geophysics V,under the supervision of Madam Saima Akbar .This was a field trip to Dhakni oil field by OGDCL to observe the drilling and extraction of oil, gas and other various products at the field. 1.2 LOCATION Dakhni oil field is located 33°24'30"N 71°56'28"E.The Daknioil field is located at a distance of about 135 Kms in the south-west of Islamabad. The field was discovered in Feb. 1983 and came on regular production in December 1989. Gas contains 6-8% H2S in the well stream. 5
  6. 6. FIELD TO DAKHNI OIL FIELD 1.3 ACCESSIBILITY Dakhni oil field is located at Kohat road near Jhand. We approached Dakhni oil field from our university by following the route toTarnol first and then we moved on Kohat road to Tehsil Jhand and from there we followed the route towards the field. 1.4 PURPOSE OF VISIT The purpose of our visit to Dakhni oil field was to understand the variousexploration techniquesobserved for oil and gas. To observe the drilling methods and the processes by which oil, gas and other products that are being extracted at the dakhni oil field and also to get a 6
  7. 7. FIELD TO DAKHNI OIL FIELD practical knowledge of the field. 7
  8. 8. FIELD TO DAKHNI OIL FIELD CHAPTER#2 PRODUCTION IN THE OIL FIELD 8
  9. 9. FIELD TO DAKHNI OIL FIELD 2.1 DHAKNI (GAS/CONDENSATE FIELD) OGDCL is the national oil & gas company of Pakistan and the flagship of the country's E&P sector. Dakhni Gas Condensate Field is located at a distance of about 135Kms in the south-west of Islamabad. The field was discovered in Feb. 1983 and came on regular production in December 1989. Gas contains 6-8% H2S in the well stream. Conditioning, treating and processing of raw natural gas/oil to obtain marketable products i.e. fuel gas, stabilized oil, motor spirit, kerosene, diesel, LPG &sulphur through processing plants via optimum safe & environment friendly process plants operation and maintenance. 2.2 PROCESSING OF HYDROCARBONS AT DHAKNI’S PROCESSING PLANT: A) SEPARATOR: Basal plants are present in separator, in which water and H2S is entered in it. Domestic pads are also there. When pressure drops due to specific gravity, as a result of which water and hydrocarbons are separated. Hydrocarbons are present in the middle of chamber, while water is in the bottom of a chamber and top of the chamber possesses gas in it. There are three types of separators: 1) horizontal 2) vertical 3) Spherical 9
  10. 10. FIELD TO DAKHNI OIL FIELD In DHAKNI plant horizontal separators are installed. When pressure abruptly goes down, than they are separated. H2S and hydrocarbon gas is forwarded. All the precautions are taken which are recommended by environmental agengy. If there is high pressure , and any breakage happens than there main feeding vent is directed towards the flares and all of the gas is burnt down , in order to remain protect from any disaster. If pressure exceeds 1265 psi than the values are opened here and the oil is burnt Acid flares/pipelines are there for oil transfer. B) ABSORBER: Chemical “AMINE” is present in the absorber. This chemical amine absorbs H2S in it. Showering of amine is taken place in the absorber and all the H2S is separated. Hydrocarbons are obtained in the range of : C1-C4 C1 : Natural gas (SNGPL – supply to homes) C2-C4 : LPG (filled in cylinders and domestically used) Chemical amine absorbs H2S and here pressure is dropped and temperature is increased and absorption level is less and H2S goes up and the amine is separated in the bottom and again the cycle continues . So, high temperature and pressure is kept in the pressure of AL2O3 catalyst. 10
  11. 11. FIELD TO DAKHNI OIL FIELD C) SULPHUR RECOVERY UNIT: Products: natural gas , LPG and sulphur. CCL3 and CCL4 presentin liquid form in the cylinders i.eLPG. Liquid hydrocarbons come in the fractional H2S is present in liquid form. High temperature is given to liquid hydrocarbons so that its boiling point became low and it becomes a gas. In the bottom inlet is present. The solubility decreases when temp. increases. 1600 Barrels/year hydrocarbons is obtained. Tanks are also present there that stores SNGL hydrocarbons. Then it is send to refinery. In a DUE POINT REDUCTION UNIT (DPRUP) high pressure and temperature is decreased , as a result of which due point is decreased according to the range. C3 and C4 are heavier hydrocarbons , their due point are less and are easily converted into liquid . C1 can easily be separated as a gas. D) REFRIGERATION UNIT: Refrigeration unit is there to cool the gas so that to convert it into the liquid. 2.3WASTE WATER TREATMENT PLANT: DHAKNI Dakhni Oil Field Water Treatment Plant is located at a distance of 120 Km from Islamabad on Islamabad – Kohat Road. The plant will supply treated water and process water to the Sulfur Recovery Plant in the Oil /Field. Raw water for the plant is abstracted 11
  12. 12. FIELD TO DAKHNI OIL FIELD from river Indus through an intake structure and is pumped the treatment plant through a M.S Main which terminates at the inlet of the Clarifier at the treatment plant where it is treated to meet the WHO Drinking Water Standards. The treatment process includes coagulation, flocculation, sedimentation, filtration, Ph-correction and disinfection. The main components of the plant include Clarifier, Medium Gravity Filters, Control Weirs, Treated Water Collection Tank, Chemical Dosing and Chlorination Equipment, instrumentation and Central Control Console. The works also included complete power distribution, electric control panels, and area lighting of the plant premises. The plant at present is operating to its full capacity and is supplying the requisite flow of treated water to the Sulfur Recovery Plant. 2.4 PROCESS DESCRIPTION: The demineralizer plant is designed to produce high purity water with low sodium leakage by Packed-bed counter-current flow technique. The resin in the vessel is packed with very limited volume of free space available with operating vessels. The flow of water being treated and regenerate flow are in opposite directions (counter-flow), the treated water leaving the bed during the exhaustion cycle will be contacting the most highly regenerated section of the resin bed, and thus extremely low concentrations of sodium will be obtained in the treated water. 12
  13. 13. FIELD TO DAKHNI OIL FIELD 2.5DESIGN BASIS: The demineralizer system capable of producing 8,000 l/hr of de-ionized water. In Coming Feed water Limit Conductivity: <500 micro Siemens Free chlorine: <0.01 mg/l Temperature: < 400C. 2.6TREATED WATER QUALITY: The water quality after the Demineraliser system will be 10 micro Siemens and below 2.7 PROBLEM FACING IN EXISTING PLANT: Previously installed PLC malfunctioning and client was running water treatment plant on manual basis. The Features of Full Auto modes were not applicable due to problems in PLC. They require a PLC system that was fully reliable and capable enough to handle the harsh acidic environment along with an HMI to operate the Plant in Fully Auto, Semi Auto and Manual Mode. 2.8 PRODUCTION ESTIMATES: GAS PRODUCTION: 45-50 million cubic feet/day. CRUDE OIL: 1600 Barrel / year. SULPHUR PRODUCTION: 65-75 tons per day. It is a sour plant because of the presence of H2S. 13
  14. 14. FIELD TO DAKHNI OIL FIELD Before going to the field we have to take the health safety precautions so as to avoid any kind of mishaps. For this there is a health safety department . 3.1 HAZARDS: H2S is a colourlessgas , possessing a rotton egg smell. It is a killer gas , that may cause death. Its specific gravity is 1.89, that can travel on the surface of earth. Sweet plant is that in which H2S is not produced along hydrocarbons. Rotten egg smell,its presence is 7% in the plant i.e ; 70,000 ppm. If 10 ppm is present in the environment than one can work about 8 hours. If the concentration is 20 ppm than one can work for only 15 min. 14
  15. 15. FIELD TO DAKHNI OIL FIELD If 100 ppm concentration of H2S exists, than sense of smell is lost. Any area in the field possessing H2S gas more than 20 ppm , than that area is considered as prohibited area. In the plant 70,000 ppm is present only in the closed system where as in the environment there is only due to the leakage in the piping system. This gas is heavier than air. One have to evacuate from that area of field if any one feel the presence of this gas (H2S). 3.2 IN CASE OF EMERGENCY: I. PROCESS CONTROL: It can be controlled through various processes. H2S is separated from the hydrocarbons, Digital meters can also be used for this purpose with alarm, if the concentration increases it automatically starts alarming. II. ERP-EMERGENCY RESPONSE PLAN: If leakage exceed the ERP comes in action and sound in the plant begins. If the concentration of H2S increases than everyone should have to evacuate the area and one should have to reach the mustard point. There are two mustard points in this “DHAKNI PLANT”. We have to see the wind direction possessing H2S gas in it. We have to go to that mustard point , which is opposite to wind direction at that particular time. So that the worker remains safe. III. FIRE CONTROL MEASURES: 15
  16. 16. FIELD TO DAKHNI OIL FIELD To control fire , fire extinguisher of DCP is present there on the field at “DHAKNI”. At dhakni , we mostly deal with liquid hydrocarbons that comes under class-B . For fire, fuel and oxygen are the essential components , so we have to remove one of them to control the fire. If fuel is removed , temperature is decreased. Foam type fire extinguishers are also used. Water is also commonly used. Hydrocarbons specific gravity is very low so foam is used which makes a layer over it and hence it cuts oxygen supply which is important for the burning process. IV. PERSONAL PROTECTIVE SAFETY MEASURES: PPE (personal protective equipments) like shoes, helmets etc are used for person’s safety. Three general things are extracted: i) Water ii) H2S iii) Hydrocarbon 16
  17. 17. FIELD TO DAKHNI OIL FIELD 3.3CONTROL AND IMPROVEMENTS Control room is used to control the temperature and pressure also measured through it. Previously there was an old plant that had a capacity of 60 tonnes but now a new plant has been installed that has a capacity of producing about 80 tonnes and it has the latest DCS system installed in it. Now a new plant (chamber) is also being built to store all the sulphur and to convert the blocks of sulphur into grains form and to improve its quality and make it more useful. The fire blazing at the tower is to burn the extra hydrocarbons produced so that environment is not contaminated and also to avoid any harmful conditions in case of emergency. 4.0 LAST WORDS: After we visited dhakni oil field, which was very educative and a marvelous academic experience. We went to their rest house 5 minutes away. It was built very nicely and reflected status of company very well. Our instructor (Sir Naveed Ahmed) was very experienceed working for about 15 years in this field. He was very clear and provided deep practical knowledge about industry. We were also shown manufacturing of sulphur. We rested their and offered prayers. Then we got fresh and were served lucnch. They had a very well kept garden which was very refreshing with a number of beautiful flowers. 17
  18. 18. FIELD TO DAKHNI OIL FIELD Then we went back to our university in islamabad. The trip was a great addition to our practical real world field knowledge and created deep intrest in us. 5.0CONCLUSION: The trip was very knowledgeable and widened our scope in our field.We came to know how oil is being produced,how different separators are used to extract different products from crude oil, how OGDCL works, and how different environmental precautions are taken at the field. 18

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