Research And Application Of Gas Drilling Technology In Sulige Gas Field

The Sulige Gas Field Areal Structure lies to the northwest of the slope of northern of Shanxi, which belongs to the E Er Duo Si Basin. Both the Data of geologic exploration and the initial drilling data indicate that the geologic condition is very complex, it is hard to explore and it will cost a lot of money, the gas bearing reservoir, which comprise of some of the horizontal composite overriding sand body, has a low press, low permeability, and low abundance, the heterogeneity of which is very strong, the per well deliverability is also very low. The investigation of the reservoir of Sulige Gas Field demonstrates that the formation pressure is lower than the static water pressure. The low pressure Gas Reservoir is also the low permeability reservoir or the ultra-low permeability reservoir, it has a strong water affinity or abundant water sensitive sialite, only using the negative differential pressure under-balance drilling with water base drilling fluid could not protect the reservoir well. Just because the reservoir is very compact, its permeability is very low, its specific surface area is very big , and it has a strong surface water wetting potential and a low initial saturation of water irreducible which formed during the forming process of the reservoir, the gas reservoir is initially very dry and water-shortage. The reservoir will suction a lot of water once the reservoir is opened by the water base drilling fluid, even under the condition of the effect of negative differential pressure. So, in order to develop the Sulige Gas Field with high efficiency, the ChangQing petroleum exploration department firstly presents a new idea of using Gas slim hole under-balance drilling to enhance the drilling speed, to shorten the drilling cycle, and to decrease the cost of development.