Reading Comprehension

PT125 · S1 · P2 · Q7 Drilling Muds

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Passage A Drilling fluids, including the various mixtures known as drilling muds, play essential roles in oil-well drilling.

Central Topic / Purpose

Drilling muds / to describe something and highlight a problem associated with it

Main Point

Drilling muds are carefully calibrated liquids important in oil-well drilling, but their complexity and the opacity of their recipes make it hard to study their environmental impact.

Central Topic / Purpose

Environmental impact of drilling muds / to describe the different environmental impacts of different drilling muds

Main Point

Water-based mud isn't very harmful and can be tossed overboard, while oil-based muds are potentially harmful and their disposal is much more tightly regulated.

Relationship

Both passages shared similar topics (drilling mud / environmental impact). Passage A felt a little more like it was trying to highlight a potential problem, while Passage B is written more in the style of neutrally describing the potential harm of OBM's. Overall, they seem pretty complementary and overlapping.

7.

Which one of the following is a characteristic of barite that is mentioned in both of the passages?

  1. It does not disperse readily

    Fails Passage A

    To be fair, even Passage B only says that OBM's, of which barite is a part, do not disperse readily. Maybe barite as a powder would. More importantly, Passage A doesn't talk at all about dispersal.

    1% picked this

  2. It is not found in

    Fails Both

    Passage A makes it seem like bentonite and barite coexist. In Passage B, bentonite is emphasized for WBMs and barite for OBMs, but it never says that barite is absent from WBMs. It only says that there are greater concentrations of barite in OBMs.

    1% picked this

  3. Its use in drilling muds

    Fails Passage A

    We don't get any info about how tightly anything is regulated in A, let alone barite.

    1% picked this

  4. It is the most commonly

    Fails Passage B

    Passage A says that barite is the biggest ingredient by weight, but that's not quite the same as saying "most commonly used". More importantly, Passage B doesn't give us any language that could support that superlative claim. For all we know, bentonite is more commonly used.

    4% picked this

  5. Correct

    It is a heavy mineral.

    Why this is right

    Passage A identifies barite as "a very heavy mineral". Passage B identifies barite as "a powdered heavy mineral".

    Skill tested: Locate Detail · how this choice captures the passage's function is the move to repeat next time.

    94% picked this

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