Research Of The Continental Gas Reservoir Protection And Reservoir Reform Technology In The Northeast Sichuan

With going deep into explorating and developing oil and gas, reservoir protection technology is increasingly becoming one of the key factors which affect efficient exploration in the development of oil and gas resources.So far we found the Northeast Sichuan area continental gas reservoirs are mainly distributed back in Yuanba structure, road back construction and dam structure.Its horizon is located in the Xujiahe group,the artesian well group and the Thousand-Buddha group. Its maximum burial depth is nearly5000m. The main producing gas reservoirs are the Xujiahe group and the artesian well group.Overall, terrestrial reservoirs in Yuanba blocks exhibit the characteristics like low-super low porosity and hypotonic-ultra-low permeability,different fractures development, lithology density, reservoir buried deep, abnormally high pressure and high formation temperature.Combined with the process of exploration drilling, cementing,oil and gas construction test do damage to reservoirs, bringing about difficult exploration and a low degree of development.Simultaneously Continental gas reservoirs of the Northeast Sichuan Yuanba area have high fracture pressure. The fracture pressure gradient of the Xujiahe is3.0-3.8MPa/100m.Under equipment and wellhead pressure limiting conditions, some characteristics exit. When fracture extends producing high pressure, this phenomenon led to injection difficulties and lower displacement.Such as low reservoir porosity, narrow cracks, fracturing fluid into the well, the acid residue which is easy to plug the pores, fluid injecting into the well which is easy to produce water lock in the low hole and so on, these secondary pollution damage greatly affect the reservoir effect of reconstruction.Shale content is high in the reservoirs and fluid backflow into the well is low (50%-80%).What is worse, fluid injecting into the well results larger secondary pollution and the poor reservoir transformation effect. Therefore, the continental gas reservoir exploration and development in the northeastern area of Sichuan, the implementation of gas reservoirs protection and reservoir stimulations technology has a vital role.Through researching theoretical studies, relevant literature as well as laboratory experiments and field implementation, this article is mainly divided into the following aspects:Concluded from the main geological features of continental gas possession in Yuanba area,its protection technology, the difficulties of continental reservoir reconstruction and transformation options, the working fluid system and compatibility of continental reservoir reconstruction, its stratigraphic test and transformation technology. we can get research achievements: According to the characteristics of the physical properties of reservoir lithology, reservoir reconstruction is preferred to form for Yuanba area in continental gas and protective gas layer formation testing and commissioning of gas technology, to form for Yuanba area of continental gas and shielding gas layer perforated completion technology, formed in continental gas suitable yuan,ba protective gas layer in acid fracturing modification techniques,Yuan ba area of continental gas and protection gas discharge seek production technology. These research development and protection of Yuanba area of continental gas layer has a vital role.