Abraxas Petroleum 8K Regulation FD Disclosure | AXAS 18 Apr 11

April 18 - 21, 2011

Exhibit 99.1

Forward-Looking Statements

The information presented herein may contain predictions, estimates and
other forward-looking statements within the meaning of Section 27A of the
Securities Act of 1933 and Section 21E of the Securities Exchange Act of
1934. Although the Company believes that its expectations are based on
reasonable assumptions, it can give no assurance that its goals will be
achieved.

Important factors that could cause actual results to differ materially from
those included in the forward-looking statements include the timing and
extent of changes in commodity prices for oil and gas, the need to develop
and replace reserves, environmental risks, competition, government
regulation and the ability of the Company to meet its stated business
goals.

AXAS Highlights

§ NASDAQ: AXAS

§ Shares outstanding: ~91.6 million

§ ~50% institutional (1)

§ ~10% insider

§ Average trading volume: ~1.5 million shares per day

§ Market capitalization: ~$525 million

§ Total long-term revolving bank debt: ~$80 million

§ High quality assets

§ Unparalleled upside opportunities

§ Significant hedge position

§ Expanded 2011 CapEx: $60 million

§ Recent equity offering: 23.6 million shares at $4.40

§ (15.1 million primary and 8.5 million secondary)

(1) Does not account for recent equity offering due to timing of filings

AXAS Assets

§ 50,000+ net acres in unconventional oil plays

§ Large inventory of unconventional and conventional drilling locations

§ Undeveloped leasehold has been largely de-risked by industry and offset operator activity

§ Undeveloped leasehold is primarily held by production

§ Substantial base of MLP-like producing properties

§ 2011 expanded budget of $60 million is 100% oil or liquids weighted

§ Secondary component of recent equity offering eliminated overhang perception

§ 3.3 million shares(1) held by the MLP investors are freely tradable

(1) Excludes 5.2 MM shares held by Lehman and 2.4 MM shares subject to lock-ups that extend to January 2012

AXAS Hedges

	2011	2012	2013	AVE.
OIL - weighted average price	$76.61	$70.89	$80.79	$75.69
% OIL PDP(1)	77%	80%	67%

GAS - weighted average price	$6.52	$6.77	$6.84	$6.69
% GAS PDP(1)	82%	81%	66%

NYMEX-based fixed price swaps:

(1) As of December 31, 2010

Net Asset Value

(1) Includes identified and resource potential on Bakken, Niobrara, Eagle Ford, Pekisko and Texas oil plays. Excludes identified and resource reserves in Alberta Basin Bakken
and $50MM value of Eagle Ford joint venture drilling carry. The probable and possible reserve estimates do not necessarily represent reserves defined under SEC rules.

Net Asset Value per Share(1)

Proved Reserves Only

$ 2.57

Proved PLUS Probable Reserves

$ 16.37

Proved PLUS Probable PLUS
Possible

$ 32.71

Proved Reserves (MMBoe)(1):
26.6

- Proved Developed: 49%

- Oil/NGL %: 42%
- Operated: 81%

Abraxas Petroleum Corporation

(1) Net proved reserves as of December 31, 2010, including
AXAS’ 50% share of Blue Eagle’s proved reserves

Bakken / Three Forks

Play

Barnett / Woodford

Shale Play

Wolfberry Trend

Rocky Mountain

Mid-Continent

Permian Basin

Gulf Coast

Eagle Ford Shale Play

High Quality Assets

Alberta

Niobrara Play

Alberta Basin

Bakken Play

Alberta

Wolfbone Play

Reserve / Production Summary

Proved Reserves(1) - 26.6 MMBoe

Production(2) - 3,621 Boepd

(1) Net proved reserves as of December 31, 2010, including AXAS’ 50% share of Blue Eagle’s proved reserves

(2) Daily net production for the quarter ended December 31, 2010

Basin

21%

Rocky

Basin

34%

Onshore Gulf

Canada

<1%

2011 Capital Budget

§ Large inventory of drilling locations in unconventional and conventional oil plays

§ 1H:11 oil weighted drilling program focused on low-risk / high-return Texas conventional
oil projects

§ 2H:11 accelerate operated drilling activity in the Bakken and Three Forks plays

§ Approximately 70% of undeveloped acreage is held by production

(1) Unrisked locations based on eight wells (four Bakken and four Three Forks) per 1,280 acre units; 160 acre spacing assumptions in the Eagle Ford and Niobrara Shale plays

(2) Eagle Ford Shale acreage and locations are gross to the Blue Eagle JV which Abraxas currently owns a 50% equity interest

Project Area	Net Acres	Net Unrisked Locations(1)	2011 Drilling Program		2011 Net Capital ($MM)
			Gross	Net
Bakken / Three Forks	20,835	130	15.0	3.0	$25.5
Eagle Ford Shale(2)	9,586	60	4.0	4.0	$0.0
Niobrara Shale	17,800	111	1.0	1.0	$5.0
Pekisko Fairway	9,120	10	2.0	2.0	$4.0
Alberta Bakken	10,000	-	-	-	-
Texas Oil Plays	8,700	65	20.0	20.0	$16.1
Other	n/a	n/a	5.0	5.0	$9.4
Total:	76,041	376	47.0	35.0	$60.0

Bakken / Three Forks

Montana North Dakota

Nesson

2,270 net acres

Elm Coulee

440 net acres

Elkhorn Ranch / Lewis & Clark

2,035 net acres

Harding / Rough Rider

7,010 net acres

Carter

3,200 net acres

Sheridan

2,340 net acres

North Fork / Nesson

3,540 net acres

§ Gross / Net Acres:

§ 109,658 / 20,835

§ ~100% held by production

§ Drilling Inventory:

§ 1,280 acre units

§ ~685 gross / 130 net

§ 4 Bakken / 4 Three Forks wells

§ Economics:

§ D&C Cost: $8.5 MM

§ EUR: 500 MBoe

§ IRR: 36% (no acreage)

§ Recent Activity:

§ 1st operated Three Forks well

(Ravin 26-35 1H; 60% WI) -

1,705 boe/d unrestricted rate

§ 1st operated Middle Bakken well
(Stenehjem 27-34 1H; 79% WI) -
completion expected in 2Q:11

§ 13 gross / 0.57 net non-operated
wells

§ 2011 Planned Activity:

§ $25.5 MM budget

§ 5.0 gross / 2.5 net operated wells

§ 10.0 gross / 0.5 net non-operated
wells

Ravin 26-35 1H - TFS

1,705 boe/d

Bakken - WOC

AXAS operated wells

Three Forks Bakken

AXAS non-operated wells location location

Bakken / Three Forks

§ Economics:

§ D&C Cost: $8.5 MM

§ EUR: 500 MBoe

§ 390 MBbl oil

§ 425 MMcf sales gas

§ 45 MBbl NGL

§ IRR: 36%

§ Ravin 26-35 1H:

§ 41,000 Boe

§ 30,500 Bbl oil

§ 32.8 MMcf sales gas

§ 5,000 Bbl NGL

3 gross (1.4 net) drilled wells

61 gross (18.3 net) development locations

2-4 Three Forks

North Fork / Nesson

3,540 net acres

79% WI

59% WI

2% WI

15% WI

6% WI

48% WI

7% WI

30% WI

Eagle Ford Shale

AXAS owns a 50% equity interest in the Blue Eagle joint venture

Drilling 44% WI

Drilling Inventory:

Nordheim Area -

§ 160 acre spacing

§ 3,600 net acres

§ 23 net wells

Eagle Ford Shale

oil window

gas window

§ Economics:

§ D&C Cost: $8.5 MM

§ EUR: 1,100 MBoe

§ 200 MBbl condensate

§ 3,500 MMcf sales gas

§ 315 MBbl NGL

§ IRR: 84%

§ T Bird 1H:

§ Cumulative production (45 days):

§ 69,000 Boe

§ 13,900 Bbl condensate

§ 201.3 MMcf sales gas

§ 21,600 Bbl NGL

AXAS owns a 50% equity interest in the Blue Eagle joint venture

T Bird 1H

DeWitt
County

West Texas - Spires Ranch

§ Economics:

§ D&C Cost: $1.6 MM

§ EUR: 160 MBoe

§ 80 MBbl oil

§ 200 MMcf sales gas

§ 45 MBbl NGL

§ IRR: 160%

§ Spires 126 1H:

§ Cumulative production (30 days):

§ 5,900 Boe

§ 3,000 Bbl oil

§ 7.3 MMcf sales gas

5,600 net acres

AXAS owns 100% working interest in Spires Ranch leasehold

Nolan
County

Business Plan

§ Expanded 2011 CapEx: $60 MM

§ oil development

§ Bakken/TFS - Prudence

§ Eagle Ford - Acceleration with JV

§ Completed divestiture program: ~$32 MM

§ non-core, predominately non-operated

§ pay down debt & accelerate CapEx

§ Target 50/50 oil/gas production mix

§ Target greater than 90% operated

§ NOL preservation

§ Increase investor interest

§ recent equity offering (150+ accounts)

§ Increase analyst coverage

§ 9 equity analyst

Appendix

(1) Eagle Ford Shale acreage and locations are net to Abraxas’ 50% equity interest in the Blue Eagle JV

(2) Possible Bakken/Three Forks locations are based on three additional Bakken and four additional Three Forks wells per 1,280 acre unit

Note: The probable and possible reserve estimates do not necessarily represent reserves defined under SEC rules

NAV - Undiscounted

2010 PV-10 at Current Pricing
($100/$4.50)

$313,084,390

Net Cash

$2,000,000

Less Outstanding Debt

($80,000,000)

Basin

Net Undeveloped
Acres

Well Spacing /
Acre

Net Locations

Per Well Reserves
(BOE)

Reserve Potential
(BOE)

Bakken / Three Forks

20,835

1280

16.3

500,000

8,138,672

Eagle Ford Shale(1)

4,793

160

30.0

500,000

14,977,766

Pekisko Fairway

9,120

10.0

150,000

1,500,000

Texas Oil Plays

8,700

65.0

57,423

3,732,500

Probable Reserve Value @$30 Netback

$1,684,843,125

Probable Reserve Value/Share (Unrisked)

$18.40

2P NAV/Share (Risked)

$16.37

Possible

Net Undeveloped
Acres

Well Spacing /
Acre

Per Well Reserves
(BOE)

Reserve Potential
(BOE)

Eagle Ford Shale(1)

4,793

30.0

500,000

14,977,766

Possible Reserve Value @$30 Netback

$2,992,829,063

3P NAV/Share (Risked)

$32.71

(1) Eagle Ford Shale acreage and locations are net to Abraxas’ 50% equity interest in the Blue Eagle JV

(2) Possible Bakken/Three Forks locations are based on three additional Bakken and four additional Three Forks wells per 1,280 acre unit

Note: The probable and possible reserve estimates do not necessarily represent reserves defined under SEC rules

NAV - PV Equivalent

2010 PV-10 at Current Pricing
($100/$4.50)

$313,084,390

Net Cash

$2,000,000

Less Outstanding Debt

($80,000,000)

Basin

Net Undeveloped
Acres

Well Spacing /
Acre

Net Locations

Per Well Reserves
(BOE)

Reserve Potential
(BOE)

Bakken / Three Forks

20,835

1280

16.3

500,000

8,138,672

Eagle Ford Shale(1)

4,793

160

30.0

500,000

14,977,766

Pekisko Fairway

9,120

10.0

150,000

1,500,000

Texas Oil Plays

8,700

65.0

57,423

3,732,500

Probable Reserve Value @$15 Netback

$842,421,563

Probable Reserve Value/Share (Unrisked)

$9.20

2P NAV/Share (Risked)

$9.47

Possible

Net Undeveloped
Acres

Well Spacing /
Acre

Per Well Reserves
(BOE)

Reserve Potential
(BOE)

Eagle Ford Shale(1)

4,793

30.0

500,000

14,977,766

Possible Reserve Value @$10 Netback

$997,609,688

3P NAV/Share (Risked)

$14.92

Eagle Ford Shale

§ Acreage:

§ 9,586 net

§ Atascosa, DeWitt, and Lavaca Counties, TX

§ Drilling Inventory:

§ 60 net JV locations

§ 160 acre spacing

§ Economics:

§ D&C Cost: $8.5 MM

§ EUR: 500 MBoe(1)

§ Blue Eagle Joint Venture:

§ AXAS operator

§ AXAS contributed 8,333 net acres

§ 50% equity interest

§ Rock Oil contributed $25 MM at closing

§ Rock Oil committed additional $50 MM

§ Upon full funding, AXAS equity interest - 25%

§ Recent Activity:

§ 1st well: T Bird 1H - On-line

§ 1st 45 day avg: 1,500 Boe/d

§ 2nd well: Matejek Gas Unit 1 - Drilling

§ 3rd well: Grass Farms 1H - 2Q:11

§ 2011 Planned Activity(1):

§ $34 MM to drill 4.0 wells

§ Funded 100% by Rock Oil

Lavaca County

Atascosa County IP Rates:

EOG: Peeler 2H: 605 bo/d

EOG: Peeler 10H: 342 bo/d

EOG: Hundley 2H: 493 bo/d

DeWitt County IP Rates:

Enduring: Keach GU 1: 3,633 boe/d

TLM: Halepeska Gas Unit 1: 2,665 boe/d

PXD: Charles Riedesel GU 1: 2,616 boe/d

HK: Oliver B 1H: 1,968 boe/d

HK: Krause 1H: 1,667 boe/d

HK: Lanik 1H: 1,404 boe/d

AXAS: T-Bird 1H: 1,500 boe/d (45 days)

oil window

gas window

gas/condensate

window

(1) 1st JV Eagle Ford well - 1,100 MBoe of proved reserves

Low Risk Oil Development

West Texas - Spires Ranch

§ Gross / Net Acres: 5,600 (100% WI)

§ County: Nolan

§ Formation: Strawn

§ Locations: 10

§ D&C: $1.6 MM / EUR: 160 MBoe

§ 2011 Capex / Activity:

§ $4.8 MM to drill 3.0 wells in 1H:11

West Texas - Shallow Howe

§ Gross / Net Acres: 2,000 (100% WI)

§ County: Ward

§ Formation: Yates

§ Locations: 40

§ D&C: $400K / EUR: 40 MBoe

§ 2011 Capex / Activity:

§ $1.6 MM to drill 4.0 wells in 1H:11

South Texas - Portilla

§ Gross / Net Acres: 1,100 (100% WI)

§ County: San Patricio

§ Formation: Frio 7,400 and 8,100 sands

§ Locations: 15

§ D&C: $700K - $900K / EUR: 47 - 88 MBoe

§ 2011 Capex / Activity:

§ $9.7 MM to drill 13.0 infill wells in 1H:11

Portilla -

San Patricio County

Spires Ranch -

Nolan County

Shallow Howe -

Ward County

ROR%:

Spires Ranch: 160%

Shallow Howe: >1,000%

Portilla: 646%

Canada Oil Development - Pekisko

§ Gross / Net Acres:

§ 9,120 (100% WI)

§ Drilling Inventory:

§ 10 gross / net locations

§ Economics:

§ D&C Cost: $2.0 MM

§ EUR: 150 MBoe

§ Recent Activity:

§ Drilled two horizontal wells to earn
leasehold position

§ 1 on-line:

§ 1st 18 day avg: 108 Boepd
(73% oil)

§ 1 shut-in pending re-completion

§ 2011 Planned Activity:

§ $4.0 MM to drill 2.0 gross / net
horizontal wells

§ Other:

§ Horizontal development of
conventional field

§ 5,400’ vertical depth / 4,000’
lateral length

Tomahawk

Twining

Pekisko Trend

Alberta, Canada

Campbell

Converse

Niobrara

Weston

Niobrara Shale

Converse / Niobrara Counties, Wyoming

CHK / EOG:

Niobrara Permit
activity

§ Gross / Net Acres:

§ 20,720 / 17,800

§ Primarily in Converse and
Niobrara Counties

§ ~90% held by production

§ ~2,100 net acres in Campbell
County directly offsetting EOG
producing well

§ Drilling Inventory:

§ 130 gross / 111 net locations

§ 160 acre spacing

§ Economics:

§ D&C Cost: $5.0 MM

§ EUR: 250 MBoe

§ Recent Activity:

§ 12 wells drilled to date
(7 horizontal / 5 vertical)

§ 1 vertical Niobrara

§ 2011 Planned Activity:

§ $5.0 MM to drill 1.0 gross/net well

§ Other:

§ 23 sq. miles proprietary 3D
seismic data

§ Full-diameter core data

EOG Crossbow Area:

3-19H: (Cum Oil 34 MBbl / Gas 145 MMcf)

2-18H: (Cum Oil 57 MBbl / Gas 428 MMcf)

15 Permits

SWN / Samson / Helis:

10 Hrz. Permits;
1 completion

CHK:

Sims 15-26H:

(Cum Oil 19 MBbl / Gas 634 MMcf)

AXAS Activity:

Sage Grouse 3H:

(Cum Oil 25 MBbl / 50 MBbl EUR)

Southern Alberta Basin - Bakken

§ Gross / Net Acres:

§ >10,000 net acres

§ 800 net mineral acres

§ Glacier and Toole Counties, Montana

§ Leases have 5-10 year primary terms

§ 2011 Planned Activity:

§ Continue to add to leasehold position in
geologically specific areas

§ Monitor industry drilling activity

AXAS Leasing Area

Blackfoot Nation Territory

Newfield Wells

Rosetta & Others Wells

Toole

Glacier

Glacier / Toole Counties, Montana

Rocky Mountain

Ø 8.4 MMBoe of proved reserves

Ø 53% proved developed

Ø 86% crude oil / NGL

Ø 1,113 Boepd of production

Ø 20.8 R/P ratio

Ø 896 gross (104 net) producing wells

Ø 72 PUD locations

Ø 81,990 net acres

Ø Primary producing basins include:

§ Williston Basin (MT and ND)

§ Powder River & Green River Basins (WY)

§ Uinta Basin (UT)

Ø Bakken / Three Forks - HBP

Rocky Mountain

Area of Operations

Overview

Net proved reserves, well count and acreage as of December 31, 2010

Daily net production for the quarter ended December 31, 2010

Alberta Basin

Bakken Play

Bakken / Three Forks

Play

Niobrara Play

Permian Basin

Ø 5.6 MMBoe of proved reserves

Ø 79% proved developed

Ø 31% crude oil / NGL

Ø 1,240 Boepd of production

Ø 12.3 R/P ratio

Ø 210 gross (156 net) producing wells

Ø 5 PUD locations

Ø 38,951 net acres

Ø Primary producing sub-basins:

§ Delaware Basin

§ Eastern Shelf

Area of Operations

Overview

Barnett / Woodford

Shale Play

Wolfberry Trend

Net proved reserves, well count and acreage as of December 31, 2010

Daily net production for the quarter ended December 31, 2010

Wolfbone Play

Gulf Coast

Ø 10.9 MMBoe of proved reserves

Ø 30% proved developed

Ø 17% crude oil / NGL

Ø 936 Boepd of production

Ø 32.0 R/P ratio

Ø 53 gross (47 net) producing wells

Ø 23 PUD locations

Ø 7,776 net acres

Ø Primary producing sub-basin:

§ Onshore Gulf Coast

Area of Operations

Overview

Eagle Ford

Shale Play

Net proved reserves, well count and acreage as of December 31, 2010

Net proved reserves, R/P ratio and PUD locations include AXAS’ share of Blue Eagle

Daily net production for the quarter ended December 31, 2010

NASDAQ: AXAS

Abraxas Petroleum (AXAS) 8-KRegulation FD Disclosure