Introduction
Our regional geology team ahs developed a list of high-potential basins and the bonanza basin is high on that list. now eight blocks are up for bid in this basin.

A team of 5 people have been tasked with evaluating these eight blocks. there is a well just outside the open blocks that encountered a good reservoir and a good source rock. unfortunately the well was dry. at the well location the source interval is immature (no HC generation)

A series of maps have been generated based on the well data and a grid of 2d seismic data. some modeling of source maturation and reservoir porosity as a function of burial depth ahs also been done.

You will use these maps to decide:
which blocks merit further work leading to a bid - good
which blocks show little HC potential - bad
which blocks are in between - possible

given figure 1. an index map showing a location of the A-1 well, the seismic lines, and the open blocks.
figure 1: illustrated a map of the the blocks, 8 blocks divided into 2 rows.
[block5, block 6, block 7, block 8
block 1, block2, block 3, and 4]
the well (information for figure 2.)is located south of block 2, near it

given figure 2. a simplified stratigraphy for the A-1 well, based on information from scouts.
in figure 2 : [at 200-250m there’s a marine shale - a potential seal . at 250-450m nearshore sandstones - a potential reservoir, sands contain brine - no hc. 600-750m there organic rich shales-potential source. good HC source characteristics - not generating oil or gas]

given figure 3. A 2d seismic lines that passes near the A-1 well location and NNE out into the basin through block 2 and block 6. in figure 3: [pictured 2d seismic survey going through block 2 and 6. potential source goes down or slopes down to the right of the image through underneath block 2 and 6. underneath it, the potential reservoir, and underneath it, potential seal. the layers is interrupted by vertical lines of cracks going though the three of them, probably faults. and it shows that block 6 is north of block 2. atop all of the layers that is sloping to the right (north) there’s a overlapping layer marked tertiary. this layer starts from mid block 2 and going thicker down to underneath block 6 and beyond.]

given figure 5 top of the potential reservoir unit based on a quick interpretation of the 2d seismic lines and a simple time-to-depth relationship. (Note: this map is adequate for for a quick-look; more careful work would be required for prospection)figure 5 shows: [an illustration of the block map (which is a division of the area into asymmetrical areas) with colored contour showing the reservoir depths. it has numbers showing depths in km, that is found in that particular block. this is for relating the depths to maturity and oil production
in block 1: 1 to 4 km
in block 2: 0.5 to 1 km
in block 3: 1 to 2.5 km
in block 4: 2 to 3.5 km
in block 5: 3 to 6 km
in block 6: 1.5 to 3 km
in block 7: 2 to 4.5 km
in block 8: 3 to 5 km]

you have on more ‘trick’ to apply to this analysis. using the well information, you model how the source rock would mature as a function of depth and how the reservoir porosity would mature as a function of depth and how the reservoir porosity would decrease with depth. the results of this modelling are shown in figure 6.

Given figure 6. modelling of source maturity (oil and gas generation) and reservoir porosity as a function of depth.
Figure 6 shows: [a graph that shows 0 to 3500m is excellent reservoir, 3500 to 4500 is intermediate reservoir, and 4500 an beyond is poor reservoir. it also shows another graph that shows that 0 to 3400m is immature, from 3400m to 4900m is oil generation, and 4900m to 6400m is gas generation]. You have a map to the top of the reservoir but not one for the source. in the well the source is 400m deeper than the reservoir, and on the seismic these intervals do not show much thickening or thinning.

Given figure 7. map of reservoir quality (porosity) based on simple modelling.
indicate on this map your preliminary estimate of reservoir quality. from figure 6, excellent reservoir quality is expected above a depth of 3500m (400-3500m). use color, shading, or or a line pattern to indicate depth above 3500m. intermediate reservoir quality is expected between 3500m and 4500m. Use a different color, shading, or line pattern to indicate this depth range. use a third color, shading, or line pattern to indicate where poor reservoir quality is expected.

given figure 8. map of source maturity (oil/gas generation) based on simple modeling. indicate on this map your preliminary estimate of source maturity. this map is for the top of the reservoir, but we will use it by assuming the source is immmature; it does not generate oil or gas. this area would be above 3000m on this reservoir map (3400-400m). use color, shading, or a line pattern to indicate depths above 3000m where the source is immature. similarly, indicate where (1) oil and (2) gas are being generated using different colors, shadings, or line patterns

Interpreted EODs
interpreted depositional environments and inferred lithologies for the primary reservoir interval.
[In the interpreted EODs or depositional environtments, there an illustration of the map (air view the area divided in blocks) and the first block all the way to 4th block (block 1,2,3,4) is just shallow marine sandstones going horizontally. while 5th to block 8 is deep basin (marines shales) going horizontally. theres’s a fan on block 5, it has the tail of a deepwater fan (sandstone and silts) going through the deep basin and the tip of the tail of the fan ends on the shallow marine sandstone. block 6 has salt in the deep basin edge line. block 7 (to the right of block 6 and above block 3) has a deepwater both fan and salt ovelaying the deep basin. while block 8 has salt on top of the fan, like over it, the salt is surrounded by the fan]

Structural traps
map of potential structural traps in the bonanza basin. note the salt ridge and anticlines in the northern tier of blocks
[in the structural traps, block 5,6,7, and 8 has a salt supported anticline going through it, through the salts in the EOD, there’s potential structural traps in every block except block 3. the traps in block 1, and block 2, 4 and 5 is on or over the shallow marine sandstones from the EOD map. the traps on block 6 is near the salt but not touching it sitting on shallow marine sandstone area. in block 5 the potential structural traps is over the fans, the trap in block 7 is sitting on the deepwater fan sandstone and silts while touching the salt.in block 8 two separate traps is over the fan and touching the salt]

HC migration map
a map showing possible buoyancy driven flow paths based on the structure (shape) of the top reservoir horizon. [in block 1, the top point is in a trap on a the sandstone reservoir. in block 2, the top is in a trap on a sandstone reservoir, in block 3, no top. in block 4, the top is in a trap on sandstone reservoir. in block 5, the top is in a trap . in block 6, the top is in a trap on a sandstone reservoir, in block 7, the top is in a trap on a deepwater fan. in block 8, 2 top point is in each trap, each is on the deepwater fan on block 8]

Your task
Based on your analysis, categorize each block into “good”, “bad” or "possible"
	consider how salt deposits and fan structure (sandstone and silts) affect the viability for oil and gas.
	consider that the shale is immature and the sandstone reservoir has no hc in the well in the depths shown on the well.
Rank the quality and maturity from depth, proximity to fans and salt, traps location, best block to the worst, in detail, considering all of the information given until now. then, rank the best blocks to drill for oil