Coll 30/146 'Oil: Bahrain Petroleum Company: Annual Reports.' [‎238r] (475/767)

- 2 -
mechanical conditions. The source of water in another hole was located and plugged,
resulting in the completion of a well that had been an unsatisfactory producer. Water
sources in two other wells were investigated and repair operations are being started
in one of these wells.
PRODUCTION
During 1940, the field produced a total of 7,073,919 barrels of oil, a daily
average of 19,328 barrels. Throughout the year oil production was held close to 20,000
barrels per day, except for a two weeks emergency period during October and November,
when the majority of the wells were shut in.
Studies show that pressure distribution within the reservoir has continued
to improve and that pressure decline is under satisfactory control. This situation has
been aided in the First and Second Pays by gas injection, the uniform field withdrawals
of the past year, and our established method of distributing those withdrawals among
wells.
Gas Injection:
Gas injection into the First Pay (Orbitoides) through Well No. 62 and into
the Second Pay through Well No. 63, was continued during the year, the gas supply being
obtained, as previously, from Fourth Pay Zone E through Well No. 51. Injection rates
into the two pays fluctuated between approximately 3,500 M.C.F. and 5,000 M.C.F. daily
and averaged approximately 4,300 M.C.F. The relatively minor changes in rate were made
in order to balance similar fluctuations in oil withdrawals. Injection volume continues
to be regulated on the policy of replacing approximately one-half the reservoir volume
of the oil withdrawn. Results to date indicate this rate to be satisfactory.
Edge Water Encroachment:
Water production for the year averaged 723 barrels per day with a daily aver
age of only 581 barrels per day during December, as compared with 840 barrels per day
during January. Although these figures represent a declining rate, individual well
studies show that the volume of edge water production is increasing slowly but steadily,
as is to be expected. The decrease in water output of the field has been brought about
by production manipulation, gas injection, and repair in certain of the larger water
producing wells.
Various special studies of the past year have increased our knowledge regard
ing the position of encroaching edge water and have contributed materially to a scientific
control of water encroachment. As reported last year, with very few exceptions, the great