Research On The Method To Identify Low Effective Circulation Channel Using Well Logging Data In Southern Xingshugang District Of Daqing Oilfield

The problem of low effective circulation channel has become one of the most important problems in the later stage of oilfield development. Daqing Oilfield has entered a period of high water cut exploitation stage, the long-term sustainability of reservoir water is leading to the early flooding, water channeling, thereby is reducing the spread of water into the area, so that has resulted in inefficient or ineffective circulation. Low effective circulation is found at the only oilfield development in recent years, has not attracted widespread attention at home and abroad. Southern Xingshugang district has entered a high water cut or super-high water cut development phase. Core analysis of inspecting well, indoor objects dynamic modulus test and field monitoring data show that inhomogeneous multi-oil layer sandstone oilfields mainly to the thick oil layer rise to 90% comprehensive saturation, there is a serious problem of ineffective and inefficient circulation. Inject water is circulated ineffectively or inefficiently in the large number of high permeability, high water cut a convenient channel ("The large pore path"). Low effective circulation channel leads to a low recovery rate, a rising production cost and a low efficiency, brings enormous pressure to the oilfield development. Therefore identifying low effective circulation channel is increasingly significant.Identifying low effective circulation channel firstly should find the large pore path in a single well log, and then bring back low effective circulation channel in the plane. Firstly the thesis studies the formation mechanism of the large pore path. Based on its microscopic changes in the logging curves, the big differences between the characteristics of the large pore path and reservoir flooded electric log characteristics are found, namely: spontaneous-potential log curve (SP) increases, natural gamma ray log curve (GR) decreases, acoustic log curve (AC) increases, lateral resisitivity log curve (RLLD/RLLS) decreases, caliper log curve (CAL) expanded, minilog curve decreases. It is recognized that the electric characteristics of super-high water cut reservoir may have great sounding features of the large pore paths. Establish interpretation model with regional characteristic in the experimental areas, we calculate reservoir parameters. The characteristics of these parameters in the large pore path are analyzed, namely: shale content, saturation of oil and the cementation intensity of the rock framework reduce; saturation of water, porosity, permeability and median grain diameter decrease. The large pore path discrimination standards are established, we identify the large pore path using a large pore path parameters method and BP neural network in the exploit region. Finally, Comprehensive geological and dynamic data, the analysis of existing oil wells and adjacent and connected relations between the injection and production wells are studied, we bring back low effective circulation channel in the plane using sedimentary facies and high permeability channels. Technology of identifying low effective circulation channel is simplified and improved.