Research And Application Of Multiple Wheel Drive - Driven Technology In Long 6 Reservoir Of Yuan 284 Block

Yuan284Chang-6Reservoir is a typical ultra-low permeability fractures reservoir in Changqing Oil Field. The matrix permeability is0.34mD to1.53mD, the apparent density of fracture in sandstones reservoir is between0.02/m and2.94/m. During the water flooding, the reservoir displayed some distinctive features:oil well production rate is low, fast production decline rate and obvious water breakthrough direction in well group. After the application of deep profile control technology, the well has low grade pressure and well group water cut declines slightly, so it is difficult to achieve ideal effect.According to current development situation in this block, in this paper the multi-round profile control and flooding technique that applicable to the multi-direction water wells of the Chang-6Reservoir was studied. To enhance the stability and profile control ability of composite profile control system, through the means of Numerical simulation technology and Core flow experiment the pre-crosslinked particle and weak gel composition and oil flooding slug combination were optimized, which is more suitable for the formation. To study the mechanism of multi-round profile control and flooding technique, produced two graphic visualization models were established. And the program design for typical well application was studied. The main results include:1) the Profile control and flooding system compound slug is composed of pre-crosslink gel particle and weak gel. The optimized formula of the weak gel is:1500mg/L polymer+100mg/L cross linking agent+100mg/L conditioning agent, the gel time is2to3days and the gel strength can be controlled. The experimental evaluation shows that The system has good properties of salt resistance, temperature resistance and water injection profile improvement, and the injection pattern is injecting0.15PV pre-crosslink gel particle before0.3PV weak gel.2) the parameters optimization experiment shows:the multi-round profile control at the middle-water-cut stage in well groups will obtain a better oil recovery efficiency. The weak gel can get into the high permeability formation with the subsequent water flooding, and the next round profile control and flooding process start before the weak gel loses efficacy can obtain the optimum efficiency. And the best round of flooding is three times.3) the results of Core flow experiment show:the multi-round flooding can get higher pressure, more homogenous water injection profile, modify the water profile and higher oil recovery than that of single flooding.the single-round flooding oil recovery is17.98%, while multi-round flooding is26.8%. 4) The mechanism of multi-round flooding is the decrease consumption of the plugging agents in a single-round flooding can increase the possibility of blocking micro fracture and then improve the flooding path and enlarge sweep efficiency.5) Field applications in Yuan294-53showed that water-cut decreased from89.8%to79.8%, and the average single well production rate increased from0.6t to1.14t.The research of multi-round profile control and flooding technique of the results achieved in this paper is not only significant for Chang-6reservoir in block Yuan284field but also can provide reference role for similar reservoirs.