494 
having multiple pay zones. The commercial oil and gas zones occur 
mainly in Miocene deposits and almost all of the reserves have been 
found at depths of less than 2,000 meters. The best prospects for 
new deposits are considered to be in the Upper and Middle Miocene 
sediments, but southern Sakhalin’s Paleocene and deep Cretaceous 
may also be petroliferous. Soviet geologists emphasize, however, that 
the key to increasing reserves is the continental shelf.*4 
Recently, the Soviets began new efforts to raise Sakhalin’s produc- 
tion. Besides increasing the use of secondary and tertiary recovery 
methods (steam injection is being used extensively to increase recovery 
of heavy oil in the Okha fields), more wildcats and deeper wells 
are being drilled. The latest success in this program was announced 
in June 1975, when a well from the Staryi Nabil fields tested at 
more than 1,750 barrels of oil per day. This was one of the most 
prolific Sakhalin wells since World War II. Significantly, Staryi Nabil 
is in the Katangli area on the Sea of Okhotsk coast and may extend 
offshore. The Soviets may do more slant drilling from coastal fields, 
such as Staryi Nabil, to produce from deposits lying partially offshore. 
This has already been done at the Odoptinskoye field to the south 
of Okha.*” 
The modest onshore production has not dampened Soviet optimism 
regarding Sakhalin’s offshore promise. The Soviets have estimated the 
potential oil reserves on the island’s coastal shelf at from 22 to 36.5 
billion barrels and the gas potential of the Sea of Okhotsk shelf 
at 11 trillion cubic feet.*® ; 
According to the Soviets both deep onshore drilling along the coast 
and offshore geophysical exploration have established that Sakalin’s 
shelf is very promising for future oil and gas discoveries. More than 
40 subsea anticlines which are considered favorable for oil and gas 
accumulation have been located. The most promising of these offshore 
areas according to the results of Russian geophysical exploration are: 
the Astrakhanovskoye uplift, in Sakhalin Gulf at the northwestern 
tip of the island; the Odoptinskoye and Piltunskoye uplifts, on the 
northeastern coast southeast of Okha; the Rymnikskoye uplift, in the 
Pogranichnoye area about half way down the eastern coast; the 
Bachinskaya offshore area, in the Aniva Gulf at the southern end 
of the island; and the Krasnogorskaya and Ilinskaya anticlines, on 
the southwestern coastal shelf.*” 
A joint Soviet-Japanese exploration program off Sakhalin in the 
Sea of Okhotsk is to get underway late in the spring of 1976 under 
a compromise settlement of a dispute that has delayed the project 
for over a year. The Japanese consortium, Sakhalin Oil Development 
Cooperation Co., recently signed an agreement, with the Soviets to 
provide financing of $152.5 million for the project. Of the total, 
$100 million is for the exploration work and is repayable with interest 
only in the event of a commercial discovery. Japan is to receive 
50 percent of any oil produced at an 8.4 percent discount from 
prevailing world prices during the repayment of the $100 million 
54 Tbid. 
55 Russia Steps Up Efforts to Boost Sakhalin Flow. The Oil and Gas Journal, July 14, 1975, p. 54. 
°° Japanese Have New Oil Target-Promising Sakhalin Island, op. cit., p. 95. 
57 Tbid. 
