Research on the Law of Liquid Production Index of Bohai Typical Oilfield Based on Big Data

The prediction of reservoir fluid production law play a key role in offshore oil field development plan design. It determines the parameter selection of pump displacement, oilfield submarine pipe capacity, platform fluid handling capacity, power generation equipment, etc. If the liquid production forecast is too low, the capacity will be expanded later, while if the forecast is too high, it will result in a waste of investment, which directly affects the fixed investment in oilfield development. Based on the statistical analysis of big data, this paper applies the dynamic data of all single wells and full life cycle of the oil field to analyze the dimensionless liquid production index (DLPI) law, and further establish the liquid production index prediction formula on this basis. Thus, the different types of Bohai plate and statistical table of the characteristics of the DLPI of the reservoir are completed. The results show that the DLPI of Bohai Sea heavy oil reservoir are following: water cut < 60 % indicates the trend is flat; water cut between 60 ∼ 80 % illustrates the slow growth (water cut 80 % is 2.5∼3 times); water cut > 80 % shows rapid growth (water cut 95% is 5.5∼6 times). The DLPI of Bohai Sea conventional oil reservoir are as following: when the water cut < 60%, the DLPI drops first, and then increase when the water cut is about 30% (the lowest point (0.7∼0.9 times)). When the water cut rise to 60%, the DLPI returns to 1 times; When the water cut is 60∼80%, it grows slowly (1.5∼2 times); when the water cut > 80 %, it grows rapidly (water cut 95% is 2∼3 times). The study may provide a guidance to the prediction of the amount of fluid in offshore oilfields, provide a basis for the design of new oilfield development schemes and increasing the production of old oilfields.