The Daqing lakes are located in the region with sub-humid continent al monsoon climate. Through historical comparison of the environment before and after oil field exploitation in the area, the paper analyses the impa...The Daqing lakes are located in the region with sub-humid continent al monsoon climate. Through historical comparison of the environment before and after oil field exploitation in the area, the paper analyses the impact of oil f ield exploitation on the eco-environment of the lakes, including the impact of diversion works, drainage works, exploitation and utilization of groundwater, dr opped crude oil and petrochemical wastewater on the lakes water body. The analys is shows that oil field exploitation caused serious pollution to soil in the lak es area and deterioration of the eco-environment. The impact became more eviden t with passage of time, and the intensity varied with areas, getting more seriou s from west to east, which meant that the eastern part of the lakes were influen ced much more seriously by the human activities. To improve the eco-environment of the Daqing lakes and make them sustainable utilization, the effective protec tion measures should be taken.展开更多
Most fault-block reservoirs in Xinmu oilfield belong to heterogeneous sandstone in characters which has low permeability, and reservoir pollution is a common phenomenon in this area. Acidizing deplugging in oil wells ...Most fault-block reservoirs in Xinmu oilfield belong to heterogeneous sandstone in characters which has low permeability, and reservoir pollution is a common phenomenon in this area. Acidizing deplugging in oil wells has become one of the major measures to improve production efficiency in the field. A compound deplug- ging technology in high efficiency low corrosion is developed for this kind of low permeability sandstone reser- voir. On the basis of profoundly understanding of the reservoir＇s physical properties and sensitivity, along with comprehensive analysis of the cause for jams in oil wells, a series of experiments are carried out in order to in- vestigate the dissolution reaction among samples and deplugging inhibitor, sample dissolving speed, formation fluid compatibility, reduction of secondary pollution, etc. Considered reservoir condition in nearby wells the op- timized compositional deplugging liquid formula is selected for this reservoir. It is featured by reducing the de- plugging reaction speed, extending solution for processing radius, preventing secondary damage in dissolution processing, and removing plug pollution effectively. To implement this high efficiency low corrosion deplugging measure based on reservoir condition in the borehole and nearby wells, a relatively better result of deplugging and production increasing is achieved, which enriches the measures to increase production in Xinmu oilfield, and this method can be applied to other similar oiffields for the purpose of maintaining the crude oil production and providing assistant for increasing the production significantly.展开更多
Drilling crews of Sinopec have encountered a series of troubles when drilling a formation called kazhdumi of Yadavaran oilfield, Iran in the last few years. The formation is buried in the depth from 3300m to 3500m, ma...Drilling crews of Sinopec have encountered a series of troubles when drilling a formation called kazhdumi of Yadavaran oilfield, Iran in the last few years. The formation is buried in the depth from 3300m to 3500m, mainly including limestone, muddy limestone and some bituminous shale. Many microfissures exist in the formation and the equivalent density of formation pore pressure ranged from 1.19g/cm3 to 1.59g/cm3. Asphalt or heavy oil kicks occurred in drilling three wells in one and a half years, which contaminated the drilling fluid and made well killing difficult due to the kicks and lost circulation in open hole. Gas and hydrogen sulfide （the concentration is up to 40000ppm） were present in the wells, and finally two wells were completely abandoned and one partially losL which frustrated the drilling engineering seriously. By analyzing the data of ＆e drilled wells, the paper summarized the causes of the troubles, and put forward suggestions and conclusions that can serve as reference and guideline for drilling well in ＆is area in the future.展开更多
文摘The Daqing lakes are located in the region with sub-humid continent al monsoon climate. Through historical comparison of the environment before and after oil field exploitation in the area, the paper analyses the impact of oil f ield exploitation on the eco-environment of the lakes, including the impact of diversion works, drainage works, exploitation and utilization of groundwater, dr opped crude oil and petrochemical wastewater on the lakes water body. The analys is shows that oil field exploitation caused serious pollution to soil in the lak es area and deterioration of the eco-environment. The impact became more eviden t with passage of time, and the intensity varied with areas, getting more seriou s from west to east, which meant that the eastern part of the lakes were influen ced much more seriously by the human activities. To improve the eco-environment of the Daqing lakes and make them sustainable utilization, the effective protec tion measures should be taken.
文摘Most fault-block reservoirs in Xinmu oilfield belong to heterogeneous sandstone in characters which has low permeability, and reservoir pollution is a common phenomenon in this area. Acidizing deplugging in oil wells has become one of the major measures to improve production efficiency in the field. A compound deplug- ging technology in high efficiency low corrosion is developed for this kind of low permeability sandstone reser- voir. On the basis of profoundly understanding of the reservoir＇s physical properties and sensitivity, along with comprehensive analysis of the cause for jams in oil wells, a series of experiments are carried out in order to in- vestigate the dissolution reaction among samples and deplugging inhibitor, sample dissolving speed, formation fluid compatibility, reduction of secondary pollution, etc. Considered reservoir condition in nearby wells the op- timized compositional deplugging liquid formula is selected for this reservoir. It is featured by reducing the de- plugging reaction speed, extending solution for processing radius, preventing secondary damage in dissolution processing, and removing plug pollution effectively. To implement this high efficiency low corrosion deplugging measure based on reservoir condition in the borehole and nearby wells, a relatively better result of deplugging and production increasing is achieved, which enriches the measures to increase production in Xinmu oilfield, and this method can be applied to other similar oiffields for the purpose of maintaining the crude oil production and providing assistant for increasing the production significantly.
文摘Drilling crews of Sinopec have encountered a series of troubles when drilling a formation called kazhdumi of Yadavaran oilfield, Iran in the last few years. The formation is buried in the depth from 3300m to 3500m, mainly including limestone, muddy limestone and some bituminous shale. Many microfissures exist in the formation and the equivalent density of formation pore pressure ranged from 1.19g/cm3 to 1.59g/cm3. Asphalt or heavy oil kicks occurred in drilling three wells in one and a half years, which contaminated the drilling fluid and made well killing difficult due to the kicks and lost circulation in open hole. Gas and hydrogen sulfide （the concentration is up to 40000ppm） were present in the wells, and finally two wells were completely abandoned and one partially losL which frustrated the drilling engineering seriously. By analyzing the data of ＆e drilled wells, the paper summarized the causes of the troubles, and put forward suggestions and conclusions that can serve as reference and guideline for drilling well in ＆is area in the future.
