摘要：As one of oil and gas storage spaces,tight sandstone reservoirs have become an important direction for oil and gas exploration in recent years,and there have been many important achievements in the exploration of tight sandstone oil and gas fields in the world.However,due to the characteristics of low porosity and low permeability in tight sandstone reservoirs,the drilling and completion process is affected by the sensitivity of the reservoir due to the intrusion of foreign fluids into the core of the formation,which further deteriorates the permeability of the reservoir and affects the exploitation of oil and gas from the formation.The Sulige gas field is located in the northern area of the Ordos Basin.The Shihezi Formation is the main natural gas production horizon.The core analysis porosity is 6-9%,with an average of 8.2%,and the permeability is 0.06-1.25mD,with an average of 0.29mD.The reservoir core contains a large amount of clay minerals.In order to clarify the reservoir sensitivity of the Shihezi Formation,the core was drilled and the characteristics of water sensitivity,alkali sensitivity,velocity sensitivity,salt sensitivity and acid sensitivity of the reservoir core were analyzed using laboratory experiments.The experiment shows that the Shihezi reservoir has strong alkali sensitivity and water sensitivity,medium salt sensitivity,velocity sensitivity and acid sensitivity.High mud content and high clay mineral content are the reasons for the water sensitivity and alkali sensitivity of the Shihezi reservoir and the low porosity and permeability.The chelating agent added during the acid sensitivity experiment can effectively improve the performance of the acid liquid and reduce the acid sensitivity of the reservoir.
关键词：Tight sandstone;reservoir sensitivity;permeability;Ordos Basin;Sulige Gas Field
