500

N°1

No2

COMPOSITE

LOG

N°6.

12/2

cemented

WATER

WATER

caves

-500

Water

BAW.

12

1000

12 1250

2750'

Water

merely be placed in such a position on the chart as to automatically correct for the distance of the derrick floor above or below the stratigraphic datum line.

At the left end of the progress chart is a composite graphic log of formations between stratigraphic datum and the bottom of the stratigraphically deepest well in the group.

All lines of correlation are horizontal on the Progress Chart. Drilling operations in any well, plotted as the work progresses can be referred across the chart to the composite log for a check on the formational progress of the work.

As formations logged in certain wells may not be logged, although present, in a well being drilled, the combination of conditions, such as water sands, caves, shells, etc., for all wells of a group, in a composite log is a useful guide, although it should not displace the ordinary crosssection for accurate work.

In preparing cross-sections, where the correlations are definitely known stratigraphie datum can be used as the base line, instead of sea level. As on the Progress Chart, this will make the lines of correlation horizontal and is a convenient method for comparison of relative depths, thickness of formations and other inter-related features.

The Progress Chart gives a graphic history of operations in all the wells of a group. For example, reading up the vertical line for August 1, 1917, on the attached Progress Chart, it is easy to tell how many wells in the group were completed or in the oil sand at that date, also what wells were drilling or standing cemented.

The Progress Chart could be used to advantage in the comparison of drilling records, either as to personnel of crews or methods of drilling. A comparison under this system would be more accurate, because of more nearly equal formational conditions, than a comparison by plotting to depths below surface.

CHAPTER III.

LOS ANGELES AND ORANGE COUNTIES.

Names of Fields.

By M. J. KIRWAN, Deputy Supervisor.

Operations requiring the attention of this office include eight developed oil fields lying within the boundaries of Los Angeles and Orange Counties.

The name Whittier-Fullerton Oil fields follows common usage to include all fields east of the city of Los Angeles; namely Olinda, Brea Cañon, Whittier, Coyote Hills, Montebello and Puente.

In addition to the above the Salt Lake field located immediately west and the Newhall field about 30 miles northwest of the city of Los Angeles, are included in the district.

Geology.

The geology of the various fields in the district was covered briefly in Bulletins Nos. 73 and 82 and other publications of the State Mining Bureau.

However, additional geological data which has been obtained since these bulletins were published will be found under the divisions relating to the various fields in the following pages.

General Statement.

The entire production of oil in this district was produced by wells in Los Angeles and Orange counties.

The data used in the following tables relative to number of producing wells and their production were taken from production reports filed by the operators with the department.

The number of wells listed; number of producing wells; number of logs filed; number of graphic logs; average daily production of oil and water per producing well (for June 1918); percentage of water and number of acres of proved oil land, are shown by fields in Table 1. "Wells Listed" include new wells, wells drilled and abandoned wells.

The following table (Table 2) is a comparison of the number of wells actually producing; their average daily production of oil and of water; average daily production per producing well; and percentage. of water, for all fields in the district during the month of June, for the last two fiscal years.

Study of the table shows that there was an increase of 91 producing wells, and an increase of 29,578 barrels in the average daily fluid production, of which 28,236 barrels were oil and 1342 barrels were water, for June, 1918 over June, 1917. The table also shows that the average daily production of oil per producing well rose from 47.6 barrels in June, 1917, to 70.0 barrels in June, 1918. The percentage of water of the total fluid production decreased from 18.8 per cent to 13.8 per cent during the same period.

Data similar to that in the foregoing tables are given under their respective fields in the following pages. It may be noted that there was little change in the number of producing wells and their production during the past year for all fields, except Coyote Hills and Montebello where there was a decided increase in the production of oil.

The following table (Table 3) shows a comparison of the average daily production of wells which were completed previous to July 1, 1917, for June, 1917 and June, 1918.

Study of table 3, shows that of the wells completed prior to July 1, 1917, there were 19 more wells producing in June, 1918, than June, 1917. This is accounted for mainly by wells which were shut down in June, 1917, and others which were undergoing repairs during this month, and which were producing in June, 1918. There are some cases where companies failed to properly report all wells producing until recently.