Quantitative Effect of Gas-oil Ratios on Decline of Average Rock Pressure

Abstract

It is recognized that in the early days of the petroleum industry oil wasproduced with practically no scientific or fundamental knowledge of the lawsand principles governing its extraction from the ground. Only a few, if any, ofthose exploiting the oil resources made any effort to collect accuratescientific information. There was little need for it, for as is frequently thecase where the supply of a natural resource appears inexhaustible and isgreater than the demand, large profits were possible from merely skimming thesurface with little regard to the efficiency or thoroughness with which the oilwas obtained. With this policy in force, great quantities of gas were wastedand when the reservoirs ceased producing by natural means they still containeda large fraction of the oil originally in them.The present tendency in the industry is toward conserving existing oilreserves. In order that greater percentages of the oil present in the groundmay be recovered, efforts are being made to improve production methods and torework depleted fields. If the production methods are to be improvedintelligently it is essential that the fundamental laws be known andunderstood, consequently large amounts of money and effort are being spent ingathering data that will serve to define and interpret these laws.A great deal of attention is being focussed on the study of the motion of oilthrough an oil-bearing sand, the forces that cause it to move and the factorsthat affect its motion. It is recognized that one of the important factors ispressure, but its quantitative effect is not known. In a given field the rateof production declines with time and so does the rock pressure.