The Application Of Monte Carlo Method In The Calculation Of Reserves And The Economic Evaluation

There are many uncertain risk factors from exploration to development of the whole process of Oil and gas fields. Geological characteristics of the reservoir,reservoir characteristics, fluid properties,production characteristics and development scheme selection, drilling method selection, economic and political factors andother uncertainties always restricts the understanding of oil and gas field development. In the development of an oilfield, we need to have an overall understanding of the oil and gas reserves for an oil-gas field since it’s an important basisfor guiding the work of oil and gas field development, economic evaluation and investment scale. So the traditional reserves calculation methods such as single reserves calculation analogy method, volume method, the value will not be sufficient to describe the uncertainty of underground oil and gas reservoirs, but the volume of oil and gas reserves calculation method is one of the most practical method, Because it does not require the production data, only need the static data of oil-gas reservoir.At the same time it’s an important basis for Monte Carlo Simulation as an Estimator of Original Oil In Place and Original Gas In Place. For a long time people do not believe the probability estimation method, people began to pay attention to the applicability of Monte Carlo method until it was widely used in various fields and gradually penetrate into the exploitation of oil andgas field.Monte Carlo method have been widely used in project investment, finance, energy production, the use of engineering calculation, hydropower, weather forecast, traffic, chemical industry, real estate, random signal processing, mining projectinvestment, resource assessment, etc. In addition, the Monte Carlo method is increasingly used in the development of oil field, such as the distribution of remaining oil, estimation, drilling time logging interpretation, reserves classification andeconomic limit rate and other fields in oil industry. The important basis of MonteCarlo method to estimate reserves is still the volumetric method. For developed and mature oil field, the basic data is relatively complete and the results calculated by volumetric method is more reliable, so we call it as a deterministic method. But for a new developed region, the available information underground isvery limited so it is difficult to obtain the accurate value of the reserves, in this case, even if the reserves parameters are available, but there is a great randomness (or uncertainty), thus affecting people a correct understanding of risk factors in the course of exploration and exploitation. Monte Carlo simulation is a Probability method that based the volume formula as spreedsbit model, this method treat all the parameters as uncertain variables in the formula and give each variable aprobability distribution, and then generate random number for random sampling and finally put the sampled valued into the Monte Carlo simulation model (volume formula),the difference between the probability method and deterministicmethod lies in the fact that the Monte Carlo method calculates a lot of reserves value.This paper made a detailed introduction to the use of Monte Carlo method to calculate the reserves of the crystal ball software, and through the examples of calculation of reserves of various parameters in the correlation between whether calculation results was studied, in addition to the application of Monte Carlo method in the field of economic evaluation is made in. Finally come to theconclusion that the Monte Carlo method is highly applicable in the calculation of reserves and economic evaluation.