In: Wagner W„ Szekely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010,1 APRS, Vol. XXXVIII, Part 7B
Natural gas forms an independent pool. Gas cap is higher than
the petroleum field and gas was found in the dissolved
condition in the petroleum. The pool is characterized by the
single hydrodynamic system characterized.
Sixteen pools are located here. Occurrence depths are from
1160m to 2710m. All pools are relating to a type of the mass-
pool roof and tectonic of shielded. Productive layers are sand
and sandstone. They are characterized by the lithological of
changeability. The sizes of oil and gas fields are small. They
occupy the limited areas in the pool in pool roof of the isolated
blocks of each bed.
The studied pool is multihorizon. The difference of depth
layer of pools exceeds 1.5 km. Prognoses of oil-and-gas
content were calculated separately for the layers that are located
at the different depths. Source of the initial information for
potential of researches are the maps of lineaments and ring
structures; they are constructed on the results of structural
interpretation of multispectral images Landsat satellite and
digital model of relief on the data of the Shutlle satellite. The
processing of results interpretation was carried out according
to the stated above technique of works. The studied pool is
multihorizon. The difference in depth of layers of pools
exceeds 1.5 km. Prognoses of oil-and-gas content were
calculated separately for the layers that are located at the
different depths. Maps of graph tightness and total length of
lineaments were created for this. These maps were created
with use of the sliding windows; the sizes of windows were
determined from the requirements of known dependence
between the sizes of a window of average value and
occurrence depth of the investigated object.
On the drilling data, disposition frequencies of pools non-
uniformly are located; they are grouped in two horizons. The
pools of overhead horizon are located at depths from 1160 m to
1950 m. The maximal quantities of pools are located on depths
about 1750 m. The gas fields for this horizon prevail. The pools
of lower horizon are located at depths from 2080 m to 2710 m.
The maximal quantities of pools are found on the depth about
2400 m. The petroleum layers are prevailing. Separate maps
of pool prognosis were created for different upper and bottom
horizons. The sizes of sliding windows were chosen taking into
account the depth values of maximal quantity of pools. Data of
23 prospecting holes were used for exploration as objects of
teaching.
For creating of maps of the potential of oil-and-gas content
the connection of objects of the forecast with meanings of the
following features was analyzed:
1) Tightness of graph and total length of lineaments for each of
8 lineament systems.
2) Remoteness from the axis of maximum of graph tightness
and total length of lineaments for all systems.
3) Tightness of graph of knots of crossing of lineaments for all
systems.
4) By the marks of hypsometry of relief; they on the digital
model of relief are determined; model is created on the
remotely sensed data.
On the result of research were determined all search features
which had influence on the location of known pools. All
analyzed features not depended from the occurrences depth.
They can be used as of the searches features. The prognosis
objects avoid both maximal and minimum values. They
conform to the intermediate values of features.
Further the probability of connection of objects of the forecast
with all complexes of attributes separately for objects of the top
and bottom horizons was appreciated and the maps of the
forecast of pools for each of horizons are constructed (Fig. 2).
A) Map of potential for B) Map of potential for
horizon 1750 m horizon 2400 m
Figure 2. Potential map of oil-and-gas content for license site in
limits of the North-Sakhalin Basin, the scale 1:50000.
Legend:
Contour of license
site
Areas are low potential
Border of
potential areas
0
Faults are interpretation on
the remotely sensed data
w
Potential regions
■
Water surface
*
High potential
areas
1 —1
Land surface
Potential areas
On the map of potential of pools are 38 percent non-potential
areas of upper horizon and 52% of the bottom horizon. The areas,
which have not received potential values, occupy 45 % and 34%
of the work area. The potential areas occupied 14 % and 11 % for
all work areas. Only 3 % of the territory has high potential for
both of maps.
The comparative analysis created of map potential showed they
have as many distinctions as they have in common. On both maps
the areas with increased meanings potential are three strips in
direction N-NW. The greatest area of maximum potential value is
located in the central part of the exploration territory. It is well
visible on maps of potential for lower and upper horizons.
Productive wells are located in the limits of this strip. The other
two strips occupy fewer areas and are characterized by lower
potential values.
Their spatial location well is coordinating with prospective on
geologic-geophysical data of pools localization, but that requires
check by test drilling.
The 21 local potential areas with the high potential values are
located on maps of potential pools within the limits of the selected
strips. Potential areas are small; their sizes are from 0.145 to 1.0
sq. km. In most cases, the planned location of the potential areas
on the prognosis maps spatially coincides with the upper and
bottom horizons.
As a result exploration is recommended to conduct detailed
seismic survey and semi-wild-cat well for two potential local
areas. Conducting complex of detailed geophysical researches is
recommended for the other three areas. The results of this
exploration will be determining the potential requirements for
drilling a prospecting hole or exploratory well.
For areas with lower potential, the explorations are executed
only after results are verified for the best potential areas.
The results of exploration allow asserting that the
investigated site is perspective as on detection of new pools within
of the known area of research and on discovery of new pools to
