OASIS PETROLEUM (OAS) $1.3bb market cap at price range mid-point of $14, Scheduled for Thursday, June 17, 2010

SUMMARY

. Not clear why OAS thinks it is worth 2.2 times book value when the properties were acquired on average at a modest discount to today’s (June 10) oil price of $75.60 . Therefore, OAS’s IPO appears to be overpriced, even at 10x after tax net present value at $61 per barrel

Acquisition history & spot oil price at the time

• June 2007, 175,000 net leasehold acres: $60 • May 2008, 48,000 net leasehold acres: $100 • June 2009, 40,000 net leasehold acres: $60 • September 2009, 46,000: $70 http://upload.wikimedia.org/wikipedia/commons/thumb/c/c7/WTI_price_96_09.svg/2000px-WTI_price_96_09.svg.png

BUSINESS

. Accumulated to-date 292,000 net leasehold acres in the Williston Basin, approximately 85% of which are undeveloped. . Currently focused on exploiting what OAS has identified as significant resource potential from the Bakken and Three Forks formations, which are present across a substantial majority of the acreage. A report issued by the United States Geologic Survey, or USGS, in April 2008 classified these formations as the largest continuous oil accumulation ever assessed by it in the contiguous United States.

GOVERNANCE

Expects to be a "controlled company" within the meaning of the NYSE rules and, as a result, would qualify for and will rely on exemptions from certain corporate governance requirements.

OPERATIONS

. Expects to operate 52% of 469 identified gross drilling locations, or 83% of 173.1 identified net drilling locations. . As of December 31, 2009, approximately 59% of total proved reserves were attributable to properties that OAS expects to operate. . Approximately 75% of the estimated 2010 drilling and completion capital expenditure budget is related to operated wells, which OAS anticipates will result in an increase in 2010 of the percentage of proved reserves attributable to properties OAS expects to operate. . As of December 31, 2009, the average working interest in operated and non-operated identified drilling locations was 58% and 14%,

OIL/GAS ACQISITION ROLL-UP

Acquisition History

• In June 2007, acquired approximately 175,000 net leasehold acres in the Williston Basin with then-current net production of approximately 1,000 Boe/d. This acreage is the core of the West Williston project area.

• In May 2008, entered into a farm-in and purchase arrangement, under which OAS earned or acquired approximately 48,000 net leasehold acres, establishing the initial position in the East Nesson project area.

• In June 2009, acquired approximately 40,000 net leasehold acres with then-current net production of approximately 800 Boe/d, approximately 83% of which was from the Williston Basin. This acquisition consolidated acreage in the East Nesson project area and established the Sanish project area.

• In September 2009, acquired an additional 46,000 net leasehold acres with then-current net production of approximately 300 Boe/d. This acquisition further consolidated acreage in the East Nesson project area.

PROVEN RESERVES

As of December 31, 2008

. $133mm post income tax, assuming $61.04 per barrel . OAS’s average per barrel price for the quarter ended March 31, 2010 was $71.04

RECENT DEVELOPMENTS

Drilling Activity as of May 31, 2010

. Since December 31, 2009, drilled nine gross (7.4 net) operated wells in the Bakken formation. Seven of these wells are on production, and two wells are being completed. Additionally, has two operated drilling rigs in the West Williston project area and two in the East Nesson project area, each of which is drilling a well targeting the Bakken formation. . All of the 16 gross (1.6 net) non-operated wells in progress on December 31, 2009 have initiated production. . Subsequent to December 31, 2009, an additional 37 gross (3.2 net) non-operated wells have begun operations with 18 gross wells on production and 19 gross wells being drilled or completed.

. Had average daily production of 3,295 Boe per day during the three months ended March 31, 2010. . Approximately 3,199 Boe per day, or 97% of the total, was produced from Williston Basin properties.

During the one month ended April 30, 2010, had average daily production of 4,044 Boe per day.

PRIVATE EQUITY OWNED PRE-IPO

. EnCap Equity Funds . "Since 1988, EnCap has been the leading provider of private equity to the independent sector of the U.S. oil & gas industry. The firm has raised 14 institutional oil and gas investment funds totaling over $7 billion and currently manages capital on behalf of over 200 U.S. and International investors."

USE OF IPO PROCEEDS

$395mm from sale of 30.4mm shares, shareholder intends to sell 11.7mm shares

. $55mm to repay debt

. $340mm for exploration