The basic idea of economic analysis of oil and gas resources is: according to the oil and gas resources and their quality of a specific unit, certain exploration work can be put into a certain period of time, and a certain oil and gas reserve can be proved theoretically. Based on this workload and reserves, the exploration economic benefits under the current oil price or various assumed oil prices are analyzed. Or conversely, according to the principle of "output-input", that is, the benefit is zero, the maximum exploration workload of a certain oil and gas reserve can be invested, that is, the economic limit of exploration investment can be calculated. Therefore, the essence of economic analysis of oil and gas resources is to express the economic value of hypothetical proven reserves in monetary form according to the geological and technical and economic data of oil and gas resources in specific areas, and then analyze the economic and social benefits of exploration. In the process of exploration and deployment, the investment direction should always be optimized according to the results of economic analysis, so that the exploration investment can be concentrated on areas and specific targets (such as local structures) that can obtain greater economic benefits as much as possible.
6.4. 1 Calculation method of investment cost
Generally speaking, in order to make a better and more comprehensive economic analysis, we should not only calculate the exploration investment, but also calculate the development investment when calculating the investment cost. The calculation of exploration and development investment cost is the basis of economic analysis of oil and gas resources.
Exploration investment mainly includes earthquake, drilling and oil testing, and other investments (including non-seismic exploration and scientific research, etc. ) spread into the above three investments respectively. So the formula is
Evaluation method and practice of oil and gas resources
In which: I- exploration investment, 10,000 yuan;
L—— total length of seismic survey line, km (or 3D seismic area, km2);
N—— the number of exploratory wells and wells;
H—— average depth of exploratory well, m;
P—— Average oil testing layers of exploration wells, layer/well;
C earthquake, C exploration, C test-earthquake, well exploration and oil testing cost quota.
Development investment includes drilling and development wells, oil and gas gathering and transportation and other engineering investments. Because in the early stage of exploration, the workload of development can only be roughly predicted, so it is estimated by a simple method. For example, the development investment of Karamay oil and gas field is estimated according to the following formula:
Evaluation method and practice of oil and gas resources
In which: I- development investment, 10,000 yuan;
1. Average investment of a single well, 10,000 yuan/well;
Ao—— oil-bearing area, km;
D—— well spacing, square kilometers; ;
F—— well pattern coefficient.
6.4.2 Financial evaluation method
6.4.2. 1 Main indicators of financial evaluation
Financial evaluation is to analyze and calculate the income and cost of the exploration project according to the current fiscal and taxation system and current price of the country, and to investigate the financial status of the exploration project such as profitability, liquidity and foreign exchange effect, so as to judge the financial feasibility of the exploration project. The main indicators of financial evaluation are financial net present value, financial internal rate of return and investment payback period, followed by investment profit rate, investment profit and tax rate, capital profit rate, domestic loan repayment period, investment debt ratio, current ratio and quick ratio. Because the parameters on which the financial evaluation is based are only inferred under certain assumptions, the reliability is poor, so it is not necessary to make a detailed analysis, and it is appropriate to adopt a simplified method for estimation. The following is the calculation method of the above three main indicators:
(1) financial internal rate of return (FIRR)
The financial internal rate of return refers to the discount rate that the present value of the annual net cash flow of the project is equal to zero in the whole calculation period, which reflects the profitability of the funds occupied by the project and is the main dynamic evaluation index to observe the profitability of the project. Its expression is as follows
Evaluation method and practice of oil and gas resources
In which: CI-cash inflow, 10,000 yuan;
Cash outflow, ten thousand yuan;
(ci-c0) t-the net cash flow in the t year;
N- calculation period, year.
For the above formula, find the FIRR value by trial interpolation. Financial evaluation should calculate the financial internal rate of return (FIRR) of all investments and self-owned funds before and after income tax, and then compare it with the benchmark internal rate of return (IC). When FIRR > IC, it is considered that its profitability has reached the minimum requirements and the project is feasible.
(2) Financial net present value (FNPV)
Evaluation method and practice of oil and gas resources
Where: IC- discount rate,%.
The financial net present value (FNPV) refers to the sum of the net cash flow of each year in the project calculation period discounted to the present value at the initial stage of construction according to the industry benchmark rate of return (12%). It is a dynamic evaluation index of project profitability. Projects with financial net present value ≥0 are acceptable.
(3) payback period of investment
Investment payback period (Pt) refers to the time required to offset the total investment with the net income of the project, generally calculated from the construction year, and the calculation formula is as follows:
Evaluation method and practice of oil and gas resources
Compare the payback period (Pt) with the industry benchmark payback period (Pc). When Pt≤Pc, it means that the investment of the project can be recovered within the specified time.
Generally speaking, when calculating the above indicators, the evaluation period is set at 65,438+05 years, mainly considering the actual main sources of funds and only considering the main taxes. The oil price is mainly based on the current oil price where the resources are located, without considering the recovery of residual value of fixed assets, possession and recovery of working capital, inflation and other factors, and several oil prices can be assumed. The general principle of evaluation is that the bigger the better, the earlier the better, based on cash flow. That is, the greater the net present value and internal rate of return, the better, and the shorter the payback period (the earlier).
Uncertainty Analysis of 6.4.2.2's Financial Evaluation
Most of the data used in financial evaluation are predicted and estimated according to the current level. Because the exploration and development cycle is long, the exploration and development objects are complex, and it is difficult to accurately predict the investment and income, not to mention all kinds of situations that may occur during the project implementation, so the economic indicators calculated in the financial evaluation are uncertain. At present, there are three main methods to analyze this uncertainty:
Breakeven analysis
Break-even analysis is based on the normal annual output, fixed cost, variable cost, taxes and other factors of the project, by determining the break-even point of the project's output (BEP, that is, the point where the project's income and cost are equal, as shown in Figure 6- 17), to analyze and predict the impact of output or capacity utilization on the project's profit and loss. The lower the break-even point, the stronger the project's ability to resist risks, the greater the possibility of profit, and the less the possibility of vice versa.
Sensitivity analysis
Sensitivity analysis is to analyze the influence of different factors of the project on the main indicators of economic evaluation (such as internal rate of return, net present value, investment payback period, etc.). ), so that decision makers can clearly understand the leading factors affecting economic indicators and improve the accuracy and objectivity of decision-making. At present, sensitivity analysis mostly adopts single factor change analysis. Because there are many changing factors in oil and gas exploration and development projects, there may be some complicated relationships between them, so it is necessary to carry out multi-factor change analysis method.
Figure 6- 17 breakeven diagram
probability analysis
Probability analysis is to determine the range and probability distribution of various factors in the project, then estimate the probability distribution of financial internal rate of return and financial net present value, and then determine the feasibility probability of the project and quantitatively determine the project risk.
National economic evaluation
National economic evaluation is to examine the economic benefits of oil and gas resources exploration from the national and social perspectives. It mainly uses shadow price, shadow wage, shadow exchange rate and social discount rate to calculate the possible net benefits of exploration projects to the national economy, thus evaluating the economic rationality of the projects. The indicators used are economic internal rate of return, economic net present value and net rate of return on investment. The calculation method of the first two indicators is the same as that of financial evaluation, and the calculation method of net investment return rate is as follows:
Evaluation method and practice of oil and gas resources
In the evaluation of national economy, there is a problem different from financial economy, that is, transfer payment. Enterprises pay taxes to the state, pay interest to domestic banks, or get some subsidies from the state. As an enterprise, with income and expenditure, financial evaluation should be considered. However, from the perspective of national economy, it has not caused the actual consumption or increase of resources. Therefore, these factors are not considered in the national economic evaluation, but only regarded as internal transfer payment.
There are some problems in the evaluation of national economy: ① Shadow parameters such as shadow price are difficult to obtain; ② The work of "cost decomposition" is complicated and its operability is poor; ③ The division of indirect cost-benefit scope lacks scientific definition.
6.4.4 Economic Limits of Exploration Investment
There are two kinds of analysis ideas.
(1) Under the condition that oil and gas resources allow, according to various specific conditions such as exploration cost quota, buried depth of oil and gas reservoirs, oil and gas quality, possible oil price, etc., analyze the minimum economic oil field reserve scale that can be recovered by oil and gas exploration investment, that is, when it is less than this reserve scale, the exploration will lose money, while when it is higher than this scale, the exploration will be profitable. So the calculation formula is as follows:
Evaluation method and practice of oil and gas resources
Where: Q0—— the reserve scale of the smallest economic oil field, 10,000 tons;
M3 M2 m 1—— Comprehensive cost of single well, ground construction cost of single well and pre-drilling exploration investment, RMB 10,000;
T—— single well exploitation period, year;
C0—— annual production cost of a single well, ten thousand yuan/year;
P—— crude oil price, RMB/ton;
S—— oil sales tax rate, RMB/ton;
Z3-unit crude oil exploitation cost, yuan/ton;
KC-recovery ratio,%;
K0-success rate of exploratory well,%.
(2) Analyze the maximum economic exploration investment in a certain scale oil and gas resource area. On this investment, you will definitely lose money, and under this investment, you may make money. This paper mainly analyzes how many reserves can be proved at most in a certain period of time, and then calculates the total value of these reserves according to the oil price, which is the limit investment in economic exploration after deducting taxes and profits. The calculation formula is as follows:
Evaluation method and practice of oil and gas resources
In which: cm- exploration quota investment, 10,000 yuan;
S—— commercial reserves, 10,000 tons;
P—— crude oil price, RMB/ton;
Z- tax, ten thousand yuan;
L- capital profit rate, decimal.