The practice of reservoir pressure maintenance by gas cycling has been adopted in many retrograde (wet) gas reservoirs to prevent condensation and ensuing loss of hydrocarbon liquids. An investigation of the factors involved in condensate recovery by gas cycling was made for this paper. The principle factors are (1) the sweep patterns developed by the cycled gas and the resulting wet gas recovery and (2) the revaporization of the liquid condensate within the reservoir upon contact by dry injected gas. It is concluded that cycling condensate reservoirs under conditions of declining pressure rather than constant pressure is advantageous both from a recovery and an economic standpoint. By operating at declining pressure, the wet gas displaced from the swept areas is recovered concurrently withwet gas recovered by gas expansion from the unswept portions of the reservoir. Any liquid condensed in the swept areas is revaporized by dry injection gas. and recovered as an enriched gas. By this mode of operation, high condensate recovery is obtained, gas sales may be possible at an earlier stage of depletion, more flexibility in field and plant operations is feasible, and reduction in investment and operating costs is achieved. Calculations of reservoir performance are presented for the Windfall Devonian Leduc reef reservoir, Alberta, Canada, exploited by this scheme. Introduction Hydrocarbon accumulations in which the fluids exhibit retrograde condensation upon reduction of reservoir pressure comprise an important and ever increasing fraction of reservoirs exploited in North America. This type of accumulation is usually described as a gas condensate or wet gas reservoir. In 1965, approximately 15% of all the reservoirs exploited in North America were of this type(l). The recovery of natural gas liquids from these accumulations must be made in the vapor phase because the liquid saturation retrograded within the pore space of the reservoir at reduced pressures is usually below the critical level at which the liquid will form a continuous phase and thus will flow or could be displaced as a liquid. When the retrograde gas reservoir is depleted solely by pressure reduction (blow-down) some or all of the following disadvantages are apparent:Loss of valuable condensate in the reservoir.Declining loading of the liquid facilities of the plant during the life of the project.Declining well productivities, which must be offset by installation of compressors and/or by drilling of additional wells. In order to prevent, or at least reduce, such a liquid loss due to retrograde condensation, the contents of gas-condensate reservoirs are often displaced through cycling operations. The wet gas is produced, stripped of liquefiable hydrocarbons and perhaps sour gases and the residual gas is reinjected into the reservoir for the purpose of displacing further wet gas. Frequently an additional make-up volume of gas is reinjected in order to maintain full reservoir pressure and prevent any retrograde condensation at all. Although cycling appears to be an ideal solution to the retrograde condensation problem, there are a number of factors which affect adversely this method of operation:

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This paper examines Canada's role as an industrialized energy-intensive consuming nation in the western world. It focuses on Canada's attitude toward the restricted utilization of its petroleum resources, petroleum being the country's main single source of energy. It examines the political wisdom and the corporate and national economics of Canada's "buy cheap and sell high" oil import/export policy and it attempts to solve, in at least a semi-quantitative way. the "risk/payoff/loss" equation of the international oil poker table at which Canada is but a four- percenter. In attempting to grapple with this complex subject, the paper first reviews Canada's role as a special member of the Organization for Economic Co-operation and Development (DECO) and the objectives of the OECD which unite the industrial nations of the western world. It then specifically considers:the pattern of energy demand and supply in the OECD community and the international petroleum trade which results from these interrelations;the results of previous supply disruptions in the unstable, but oil-rich, OPEC block which feeds the DEOD nations with oil, and the impact of such disruptions on Canada;the possibility, nature and magnitude of future oil supply disruptions, the resultant scenario, and the impact that they would have on Canada in both physical and economic terms having regard to existing and potential back-up sources of oil supplies. Finally, the paper attempts to quantify the real cost/ price economics of international integrated producer/ refiners operating in Eastern Canada, for the purpose of determining the profit incentive driving such companies to maintain the status-quo; it also provides the basis of a fundamental benefit/cost study of Canada's oil import policy, without which scrutiny of the "N.O.P." becomes an entirely qualitative exercise (to be presented in Part II). The paper suggests that the security of Canada's imported oil supplies is diminishing with time due to the current near capacity situation of the aging U.S. and Venezuelan oil industries. It also develops as a basic theme Canada's obligations to the OECD community and the premise of sharing remaining supplies among the energy-hungry DECD countries in times of oil supply disruptions. Because of this concept, the paper notes that a supply disruption amounting to some 20 per cent of OECD demand would be magnified to have double that effect on Eastern Canada. The paper concludes that Canada is pursuing a policy on oil imports which both jeopardizes the economic security of Eastern Canadians, through exposing them to a growing uninsured oil supply risk and runs against the public interest of Canadians as a whole from a national cost/benefit point of view. The authors recommend that Canada should take a much closer and more sophisticated look at the changing situation in, view of their preliminary findings. They also suggest that a connection to domestic sources of supply could provide coverage of the security risk noted.

The practice of reservoir pressure maintenance by gas cycling has been adopted in many retrograde (wet) gas reservoirs to prevent condensation and ensuing loss of hydrocarbon liquids. An investigation of the factors involved in condensate recovery by gas cycling was made for this paper. The principle factors are (1) the sweep patterns developed by the cycled gas and the resulting wet gas recovery and (2) the revaporization of the liquid condensate within the reservoir upon contact by dry injected gas.

The investigation of foreign investment opportunities should be approached with the same degree of sophistication and knowledge as that available for U.S.A. and Canada. The foreign risk taker should identify and become knowledgeable about variables that might affect his investment, which refers particularly to the political and economic environments. In making the decision to enter into and type of foreign venture, we should overcome the habit or custom of analysing the foreign investments within the same framework we apply to domestic investments in U.S.A. and/or Canada, utilizing the same assumptions, analytical tools and instructions that have resulted in investment success in the considerably less complicated North American economic-political systems. Some of the principal variables which should always be studied are: Technical and Engineering (Geological); Financial; Economic and Legal; Marketing, Pricing, Competition; Political and Social. The key to profitable ventures in foreign countries, particularly in the developing countries, will lie then in the future, in the motivation generated by the inevitable increase of political, social and competitive pressures. The paper discusses in detail the individual most important sections of the political, economic and social intelligence and their quantitative and -relative importance in the final decision-making process of entering into a foreign venture. INTRODUCTION DESPITE heady references in business literature concerning the trend toward corporate multinationalism, the fact remains that many North American firms large and small - approach foreign investment opportunities with much less sophistication and confidence than they exhibit in the domestic environment. This is particularly true when the prospective investment relates to a less developed country. Since the end of 'World War II, enormous changes have taken place in international business. World trade has been the fastest growing major economic variable, with the exception of the growth of direct foreign investment activities, as shown below: Although the book value of "North American" foreign investments increased about seven times during the last 20 years, the total assets, which currently are valued by at least 70 per cent higher, increased during the same period about 12 times. Approximately 4,500 "North American" companies have at least one foreign operation, although about 210 of these companies control 75 per cent of the total foreign assets. The importance of these multinational companies is not so much in their size, but their concentration in specific few key industries, such as oil, chemicals, electronics, computers, automobiles, machinery, transportation and instruments. The oil industry is probably the most classical example of such multi-nationality. At the end of 1970, the world oil industry's gross investments in fixed assets, excluding investments in the U.S.A. and in Canada, amounted to some $97 billion, i.e. 57 per cent of all foreign investments in the entire world. The investments of American companies, outside North America, were $41 billion, which represents 51 per cent of the total U.S.A. foreign investments. During the 1960's, income received by U.S. oil- companies from these operations, excluding Canada, was twice as great as that received from all other U.S. foreign investments combined.