Production And Prevention Of Hydrogen Sulfide During SAGD Process In Du 84 Well Block From Liaohe Oilfield

Liaohe oilfield is the largest heavy crude oil and super heavy crude oil production basement in china,The Du 84 well block located in Shuyiblock area was carried on SAGD development technology which has greatly improved the development of super heavy crude oil,and now this technology has reached the international advanced level,but at the same time as the other thermal recovery process which also produce a secondary type hydrogen sulfide gas in different degrees and thus brings huge hidden trouble to field personnel safety production.This paper conducts the study on formation cause of the high concentration of hydrogen sulfide in SAGD development and identify the causes of hydrogen sulfide,which playsan important guiding role in the late production process and the prevention and control of hydrogen sulfide.Based on a large number tests of oil,gas,water,rocks,additives,the geochemical and the analysis of the sample,the paper combines multidisciplinary cross technical route,theories with practice and at same time conducts a lot of experimental comparison and analysis on comprehensive research.The results show that the hydrogen sulfide of Liaohe Oilfield SAGD development is mainly from the secondary decomposition of pyritein the reservoir sandstones,andthe sulfur pyrolysis of oil organic matter(TDS)and thermochemical sulfate reduction(TSR)reactions are also sources of hydrogen sulfideand,as described it is a complex unity between the various interrelated causes of hydrogen sulfide.Through the research analysis it is found out that the main controlling factor concentration of hydrogen sulfide does not only depend on the effect of the distribution of reservoir geology conditions,but also effected bythe development mode,the development time,heating temperature and other factors,among which the temperature and time are the main controlling factors.Hydrogen sulfide gas will always exist during theSAGD development process,whilethe overall size of the output with temperature and concentration and development time whether will change or not still need using physical simulation analysis and whichneeds further study.The results also show that the thermal recovery process of heavy crude oil brings out other toxic gases more than just hydrogen sulfide,as well as other complex component sulfides,mercaptans,amines and so on,but also the amine component which was not previously noticed by humane and since its volume may also be large,the potential hazards may be greater.A reasonable governance programs applicable project of Liaohe Oilfieldhas been designed byidentified the source of hydrogen sulfide causes,based on the analysis of the toxicity and hazards,explicit hydrogen sulfide toxicity grading clear harm to human body and the metal column,equipment corrosion hazards,compared analysis of hydrogen sulfide gas conventional treatment methods and the latest treatment methods,binding site of the oil field production process and conditions.And the project is the basis for Liaohe Oilfield SAGD development six methods for the prevention and control of production processes carried out follow-up of toxic and hazardous gases.