Drilling and Production Technique in the Baku Oil Fields

Abstract

No oil territory in the world has been so rich in large producing wells, ina comparatively small area, as the Baku field. Particularly is this true of theBibi Eibat field, which formerly produced millions of ?poods? of ?gusher,? oras it is called in Russia, ?fountain? oil. The Bibi Eibat and Balachany fieldshave been exhausted of gas and ruined by water, but, the Surachany andBenegadi fields are still fountain territories and many outlying districts thathave only been prospected produce rich fountains. The method of controlling fountains, or gushers, is the result of growth, alongwith the Russian system of drilling, where large diameters and riveted casinghave been in vogue. The screw casing is seldom used except to exclude water.Formerly the method of finishing wells and the condition of the casing at thetop of the well would not permit the use of gates, manifolds, and connectionsas is standard elsewhere. The life of the flowing wells is very short, particularly those 10 in. (25 cm.)or more in diameter, which produce large quantities of sand and often flow forbut a few days and are then a complete loss. More than 1,000,000 poods in 24hr. have been claimed in several instances, but in no case was the flow formore than a few days. The oil sands of this district are free uncemented sands and vary in thicknessfrom paper thin to a maximum of 10 ft. (3 m.). The sands are interlaid withstrata of soft clay. In spite of this, the practice has been to drill into suchsands and produce from the open hole without screen or liners. Sometimes thecasing is set below the oil sand but in this case holes from 2? to 3 in. indiameter are drilled opposite the oil sand, which would not have the effect ofa screen. Fig. 1 is an outline of the fountain shield ready for the control of afountain. It is composed of an inner and an outer covering made from roughboards. The framework is made of rough round poles. When a light flow isexpected, only the inner lining is built; and when the fountain comes inunexpectedly, it is often possible to build only the outer cover. The bridge isfor the purpose of renewing the blocks as they become worn by the flow. Thelower block, as here shown, is made of hardwood and is bolted to the crossbeamswith brass bolts. The grain end is toward the flow. The upper block, as shownhere, is made of cast steel and is also bolted to the cross beam with brassbolts. AIME 065–42