Study on Development Applicability of Highly Deviated Wells in Mahu Deep Tight Oil

Mahu deep tight reservoir in Junggar basin has the characteristics of deep burial, thin and dispersed oil layers and many interlayer. The EUR of single well produced by vertical well and horizontal well is low, so it is difficult to realize the economies of scale of reserves. In order to clarify the effective development mode of Mahu deep tight oil, taking Mahu deep M reservoir as an example, the development comparison of different well types is carried out, and the applicability of the development mode of highly deviated wells is further explored. A multi-layer stacked reservoir model is constructed based on typical wells. The development effects of three different well types, vertical well, horizontal well and highly deviated well, are compared by means of production analysis and numerical simulation. The influence difference of interlayer interference during multi-layer combined production of different well types is quantitatively evaluated by indicators such as single well EUR and production loss rate, Further, the applicable interlayer thickness and economic limit for highly deviated wells are established. The results show that the apparent reservoir thickness of highly deviated wells is greater than that of vertical wells, and the initial production is 1.8–2.3 times that of vertical wells; The production loss rate of highly deviated wells in double-layer mining is 11.2%, and the loss rate of three-layer combined production is 12.2%. The production interference loss rate is lower than that of vertical wells, therefore, it is more advantageous to use highly deviated wells for the development of reservoirs with thinly dispersed and multi-interbed reservoirs. The interlayer interference decreases with the increase of interlayer thickness. The applicable interlayer thickness limit for highly deviated wells is 22–26 m.