NEW YORK ( TheStreet) -- Holly Energy Partners ( HEP), Idemitsu Kosan ( IDKOY), Linc Energy ( LNCGY) and STR Holdings ( STRI) were top gainers last week, while SandRidge Energy ( SD) Forest Oil Corporation ( FST), Brigham Exploration ( BEXP), Vestas Wind Systems ( VWDRY), RPC ( RES) and Dril-Quip ( DRQ) were top losers.

Holly Energy Partners advanced 2.4%, the highest gainer in a week when most energy stocks ended in the red.

Idemitsu Kosan, in the wake of better-than-expected earnings, rose 1.6%. Net profit soared to $750 million. According to International Resource News, the company is in discussions to invest in the Nghi Son refinery project in Vietnam.

Linc Energy rose by a marginal 0.2%.

STR Holdings moved higher on better-than-estimated results. First-quarter sales were $92.9 million, compared to an estimated $92.9 million. Adjusted EPS was 33 cents against the estimated 32 cents.

SandRidge was the top loser, declining 16.2% during the week after reporting disappointing earnings. Net loss for the first quarter of 2011 was $10.1 million against an estimated profit of $5.4 million. Last year, net profit for the same quarter was $12.42 million. Consequently, EPS was negative at 2 cents, compared to estimates of 1.8 cents for the quarter.

First Oil dipped 15.8% during the week after failing to meet EPS and revenue estimates. The company reported first quarter EPS of 19 cents against the estimated 34 cents. Revenue was $203.1 million compared to $232.4 million in the quarter.

Brigham Exploration plunged 15.4% during the week.

Vestas Wind Systems lost 15.1% on a brokerage downgrade. Goldman Sachs cut Vestas to neutral on weak first quarter results. The brokerage firm cut the price target to DK180 ($34.60) from DK220 ($42.30).

Other decliners were RPC, Dril-Quip and Unit Corporation ( UNT), down 14.8%, 14.7% and 14.4%, respectively.

SM Energy ( SM) shed 14% after a brokerage downgrade. Equity analyst David Tameron of Wells Fargo cut SM Energy stock to market perform from outperform.

Imarex Energy ( XEC) declined 13.8% last week on lower-than-estimated EPS. For first quarter 2011, EPS was reported at $1.37 per share, compared to the consensus estimate of $1.58. Revenue for the quarter slipped 5% to $426.6 million from the same period last year, beating the consensus estimate of $413.7 million.

Comstock Resources ( CRK) shed 13.6% during the week.

Helmerich & Payne ( HP) declined 13.1% last week on a brokerage downgrade. Equity analyst Charles Minervino of Susquehanna downgraded the stock to neutral from positive. The 12-month target price is $72 per share.

Pioneer Natural Resources ( PXD) slumped 12.9% last week.

OGX Petroleo ( OGXPY) fell 12.7% last week. UBS cut the stock's price target on the expectation that first crude oil production from the Waimea prospect could be delayed. The company reported a net loss of $33.9 million in the first quarter compared to $56.9 million in the same period last year.

Helix Energy Solutions ( HLX), Gasprom OAO ( OGZPY), Concho Resources ( CXO), Technip ( TKPPY), Petroleum Geo Services ( PGSVY), Atlas Energy ( ATLS) and Atlas Pipeline Partners ( APL) wiped out 12.6%, 11.8%, 11.7%, 11.5%, 11.5%, 11.4% and 11.4%, respectively.

Murphy Oil Corporation ( MUR) lost 11.4% during the week. The company's lower-than-expected second-quarter production guidance did not excite the market. Besides, JPMorgan has an underweight rating on the stock with a price target of $73.4.

Oil giants ConocoPhillips ( COP), Royal Dutch Shell ( RDS/A), Petroleo Brasileiro ( PBR) and Total ( TOT) erased 7.5%, 7.3%, 8% and 8.1%, respectively.