关键词: 水平井, 孔隙动用, 剩余油, 高含水期, 核磁共振

Abstract:

Based on the three-dimension physical model experiment to simulate water flooding and the nuclear magnetic
resonance imaging（MRI）as well as the T2 spectrum measuring techniquein this paper，we establish a series of laboratory
experiment methods to study the pore scale producing mechanism of horizontal well development in the high water cut stage.
With the experiment methods，the residual oil distribution and different pore scale producing mechanism of horizontal well
development for Ng5–6 strata is further studied. The results show that the relative oil saturation in small pores varies with the
degree of displacement，but the relative oil saturation in middle-large pores is almost the same. During the whole displacement
progress，middle-large pores act most actively. Until the relative oil saturation of reservoir reduces to an extent，the oil in small
pores begins to be produced. The producing extent of small pores is even larger than the middle and large pores when the relative
oil saturation of reservoir reduces to an extent because of imbibition effect. The horizontal well is an effective way to develop
small pore. The effect on developing residual oil is especially significant to the main flow area. The central area is critical to
the recovery.

Key words: horizontal well, producing extent of pores, residual oil distribution, high water cut stage, NMR