STUDY ON CONCEPTUAL MODEL OF OIL AND WATER DISTRIBUTION IN WELL GROUP TK461 OF ORDOVICIAN RESERVOIR IN TAHE OILFIELD, TARIM BASIN, CHINA

The reservoir space of the Ordovician dense carbonate in Tahe Oilfield,the Tarim Basin,is a complex system,mainly composed of one or several large pipeline-shaped cavities which were communicated by natural and acid-fracturing fractures.The development performance shows that there are a number of different invading pathways of edge or/and bottom water bodies in Well Group TK461,which are different from the common water invading process from lower to higher position gradually.After water injection from Well TK461 in the lower-position,water production in Well TK432 decreased and Well TK435 produces no water but pure oil.The conceptual model of oil and water distribution has been established in Well Group TK461 according to the relationship between water and oil during the development.The model reveals that water injection from a well in the lower position may increase the energy of remaining oil in the wells in the upper position wells-from the reverse direction of the original invading pathway,resulting in water containing drop and control water coning in wells in the upper position.