Exhibit 99.1
 (NSAII LOGO)
    
    CHAIRMAN & CEO
    
    EXECUTIVE COMMITTEEC.H.(Scott) Rees III
    
    P. Scott Frost  DallasPresident & Coo
    
    J. Carter Henson, Jr.  HoustonDanny D. Simmons
    
    Dan Paul Smith  DallasExecutiveVP
    
    Joseph J. Spellman  DallasG. Lance Binder
    
    Thomas J. Tella II  Dallas
  
    Net Reserves
    
    
    Future Net Revenue (M$)Oil
    
    
    Gas
    
    
    
    
    
    
    Present WorthCategory
    
    (MBBL)
    
    
    (MMCF)
    
    
    Total
    
    
    at 10%Proved Developed Producing
    
    
    13,162.6
    
    
    
    54,388.1
    
    
    
    392,005.1
    
    
    
    467,081.9Proved Developed Non-Producing
    
    
    11,837.1
    
    
    
    120,488.5
    
    
    
    860,087.8
    
    
    
    531,752.5Proved Undeveloped
    
    
    8,203.1
    
    
    
    99,829.9
    
    
    
    451,236.5
    
    
    
    188,385.4Total Proved
    
    
    33,202.7
    
    
    
    274,706.4
    
    
    
    1,703,329.4
    
    
    
    1,187,219.8
 Totals may not add because of rounding.
    4500
Thanksgiving Tower  1601 Elm Street 
 Dallas, Texas 75201-4754  Ph:
 214-969-5401  Fax: 214-969-5411
1221 Lamar Street, Suite1200  Houston, Texas77010-3072  Ph: 713-654-4950  Fax: 713-654-4951
    
    nasi@nsai-petro.com
netherlandsewell.com




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Sincerely,NETHERLAND, SEWELL & ASSOCIATES, INC.Texas Registered Engineering Firm F-002699By:
    /s/ C.H. (Scott) Rees IIIC.H. (Scott) Rees III, P.E.Chairman and Chief Executive OfficerBy:
    /s/ Richard B. Talley, Jr.
    
    By:
    /s/ Patrick L. HiggsRichard B. Talley, Jr., P.E. 102425
    
    
    Patrick L. Higgs, P.G. 985Vice President
    
    
    Vice PresidentDate Signed: January 19, 2011
    
    
    Date Signed: January 19, 2011




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DEFINITIONS OF OIL AND GAS RESERVES
  Acquisition of properties.
 Analogous reservoir
 (i)
    
    Same geological formation (but not necessarily in pressure communication with the reservoir of
interest);(ii)
    
    Same environment of deposition;(iii)
    
    Similar geological structure; and(iv)
    
    Same drive mechanism.
 Instruction to paragraph (a)(2)
 Bitumen
 Condensate
 Deterministic estimate
 Developed oil and gas reserves
 (i)
    
    Through existing wells with existing equipment and operating methods or in which the cost
of the required equipment is relatively minor compared to the cost of a new well; and(ii)
    
    Through installed extraction equipment and infrastructure operational at the time of the
reserves estimate if the extraction is by means not involving a well.
 Supplemental definitions from the 2007 Petroleum Resources Management System:Developed Producing Reserves  Developed Producing Reserves are expected to be recovered from
completion intervals that are open and producing at the time of the estimate. Improved recovery
reserves are considered producing only after the improved recovery project is in operation.Developed Non-Producing Reserves  Developed Non-Producing Reserves include shut-in and
behind-pipe Reserves. Shut-in Reserves are expected to be recovered from (1) completion
intervals which are open at the time of the estimate but which have not yet started producing,
(2) wells which were shut-in for market conditions or pipeline connections, or (3) wells not
capable of production for mechanical reasons. Behind-pipe Reserves are expected to be recovered
from zones in existing wells which will require additional completion work or future
recompletion prior to start of production. In all cases, production can be initiated or restored
with relatively low expenditure compared to the cost of drilling a new well.
 Development costs.
 (i)
    
    Gain access to and prepare well locations for drilling, including surveying well locations
for the purpose of determining specific development drilling sites, clearing ground, draining, road
building, and relocating public roads, gas lines, and power lines, to the extent necessary in
developing the proved reserves.(ii)
    
    Drill and equip development wells, development-type stratigraphic test wells, and service
wells, including the costs of platforms and of well equipment such as casing, tubing, pumping
equipment, and the wellhead assembly.
 Definitions-Page 1 of 6




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DEFINITIONS OF OIL AND GAS RESERVES
 (iii)
    
    Acquire, construct, and install production facilities such as lease flow lines,
separators, treaters, heaters, manifolds, measuring devices, and production storage tanks,
natural gas cycling and processing plants, and central utility and waste disposal systems.(iv)
    
    Provide improved recovery systems.
 Development project
 Development well
 Economically producible
 Estimated ultimate recovery (EUR)
 Exploration costs
 (i)
    
    Costs of topographical, geographical and geophysical studies, rights of access to properties to
conduct those studies, and salaries and other expenses of geologists, geophysical crews, and others
conducting those studies.
Collectively, these are sometimes referred to as geological and geophysical or G&G costs.(ii)
    
    Costs of carrying and retaining undeveloped properties, such as delay rentals, ad valorem
taxes on properties, legal costs for title defense, and the maintenance of land and lease
records.(iii)
    
    Dry hole contributions and bottom hole
contributions.(iv)
    
    Costs of drilling and equipping exploratory
wells.(v)
    
    Costs of drilling exploratory-type stratigraphic
test wells.
 Exploratory well
 Extension well
 Field
 Oil and gas producing activities
 (i)
    
    Oil and gas producing activities include:
 (A)
    
    The search for crude oil, including condensate and natural gas liquids, or natural gas
(oil and gas) in their natural states and original locations;(B)
    
    The acquisition of property rights or properties for the purpose of further exploration
or for the purpose of removing the oil or gas from such properties;(C)
    
    The construction, drilling, and production activities necessary to retrieve oil and gas
from their natural reservoirs, including the acquisition, construction, installation, and
maintenance of field gathering and storage systems, such as:
 (1)
    
    Lifting the oil and gas to the surface; and(2)
    
    Gathering, treating, and field processing (as in the case of processing gas to extract
liquid hydrocarbons); and
 Definitions-Page 2 of 6




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DEFINITIONS OF OIL AND GAS RESERVES
 (D)
    
    Extraction of saleable hydrocarbons, in the solid, liquid, or gaseous state, from oil
sands, shale, coalbeds, or other nonrenewable natural resources which are intended to be
upgraded into synthetic oil or gas, and activities undertaken with a view to such
extraction.
 Instruction 1 to paragraph (a)(16)(i): The oil and gas production function shall be regarded as
ending at a terminal point, which is the outlet valve on the lease or field storage tank. If
unusual physical or operational circumstances exist, it may be appropriate to regard the
terminal point for the production function as:
 a.
    
    The first point at which oil, gas, or gas
liquids, natural or synthetic, are delivered to a main pipeline, a common carrier, a refinery,
or a marine terminal; andb.
    
    In the case of natural resources that are intended to be upgraded
into synthetic oil or gas, if those natural resources are delivered to a purchaser prior to
upgrading, the first point at which the natural resources are delivered to a main pipeline, a
common carrier, a refinery, a marine terminal, or a facility which upgrades such natural
resources into synthetic oil or gas.
 Instruction 2 to paragraph (a)(16)(i):For purposes of this paragraph (a)(16), the term saleable
hydrocarbonsmeans hydrocarbons that are saleable in the state in which the hydrocarbons are
delivered.
 (ii)
    
    Oil and gas producing activities do not
include:
 (A)
    
    Transporting, refining, or marketing
oil and gas;(B)
    
    Processing of produced oil, gas, or natural resources that can be upgraded into synthetic
oil or gas by a registrant that does not have the legal right to produce or a revenue interest in
such production;(C)
    
    Activities relating to the production of natural resources other than oil,
gas, or natural resources from which synthetic oil and gas can be extracted; or(D)
    
    Production of
geothermal steam.
 Possible reserves.
 (i)
    
    When deterministic methods are used, the total quantities ultimately recovered from a
project have a low probability of exceeding proved plus probable plus possible reserves. When
probabilistic methods are used, there should be at least a 10% probability that the total
quantities ultimately recovered will equal or exceed the proved plus probable plus possible
reserves estimates.(ii)
    
    Possible reserves may be assigned to areas of a reservoir adjacent to probable reserves
where data control and interpretations of available data are progressively less certain.
Frequently, this will be in areas where geoscience and engineering data are unable to define
clearly the area and vertical limits of commercial production from the reservoir by a defined
project.(iii)
    
    Possible reserves also include incremental quantities associated with a greater percentage
recovery of the hydrocarbons in place than the recovery quantities assumed for probable
reserves.(iv)
    
    The proved plus probable and proved plus probable plus possible reserves estimates must be
based on reasonable alternative technical and commercial interpretations within the reservoir or
subject project that are clearly documented, including comparisons to results in successful
similar projects.(v)
    
    Possible reserves may be assigned where geoscience and engineering data identify directly
adjacent portions of a reservoir within the same accumulation that may be separated from proved
areas by faults with displacement less than formation thickness or other geological
discontinuities and that have not been penetrated by a wellbore, and the registrant believes
that such adjacent portions are in communication with the known (proved) reservoir.
Possible reserves may be assigned to areas that are structurally higher or lower than the
proved area if these areas are in communication with the proved reservoir.(vi)
    
    Pursuant to paragraph (a)(22)(iii) of this section, where direct observation has defined a
highest known oil (HKO) elevation and the potential exists for an associated gas cap, proved oil
reserves should be assigned in the structurally higher portions of the reservoir above the HKO
only if the higher contact can be established with reasonable certainty through reliable
technology. Portions of the reservoir that do not meet this reasonable certainty criterion may
be assigned as probable and possible oil or gas based on reservoir fluid properties and pressure
gradient interpretations.
 Probable reserves.
 (i)
    
    When deterministic methods are used, it is as likely as not that actual remaining quantities
recovered will exceed the sum of estimated proved plus probable reserves. When probabilistic
methods are used, there should be at least a 50% probability that the actual quantities
recovered will equal or exceed the proved plus probable reserves estimates.




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DEFINITIONS OF OIL AND GAS RESERVES
 (ii)
    
    Probable reserves may be assigned to areas of a reservoir adjacent to proved reserves where
data control or interpretations of available data are less certain, even if the interpreted
reservoir continuity of structure or productivity does not meet the reasonable certainty
criterion. Probable reserves may be assigned to areas that are structurally higher than the
proved area if these areas are in communication with the proved reservoir.(iii)
    
    Probable
reserves estimates also include potential incremental quantities associated with a greater
percentage recovery of the hydrocarbons in place than assumed for proved reserves.(iv)
    
    See also guidelines in paragraphs (a)(17)(iv) and (a)(17)(vi) of this section.
 Probabilistic estimate.
 Production costs
 (i)
    
    Costs incurred to operate and maintain wells and related equipment and facilities, including
depreciation and applicable operating costs of support equipment and facilities and other costs
of operating and maintaining those wells and related equipment and facilities. They become part
of the cost of oil and gas produced. Examples of production costs (sometimes called lifting
costs) are:
 (A)
    
    Costs of labor to operate the wells and related equipment and facilities.(B)
    
    Repairs and maintenance.(C)
    
    Materials, supplies, and fuel consumed and supplies utilized in
operating the wells and related equipment and facilities.(D)
    
    Property taxes and insurance applicable to proved properties and wells and related
equipment and facilities.(E)
    
    Severance taxes.
 (ii)
    
    Some support equipment or facilities may serve two or more oil and gas producing activities
and may also serve transportation, refining, and marketing activities. To the extent that the
support equipment and facilities are used in oil and gas producing activities, their
depreciation and applicable operating costs become exploration, development or production costs,
as appropriate. Depreciation, depletion, and amortization of capitalized acquisition,
exploration, and development costs are not production costs but also become part of the cost of
oil and gas produced along with production (lifting) costs identified above.
 Proved area.
 Proved oil and gas reserves.
 (i)
    
    The area of the reservoir considered as proved includes:
 (A)
    
    The area identified by drilling and limited by fluid contacts, if any, and(B)
    
    Adjacent undrilled portions of the reservoir that can, with reasonable certainty, be
judged to be continuous with it and to contain economically producible oil or gas on the
basis of available geoscience and engineering data.
 (ii)
    
    In the absence of data on fluid contacts, proved quantities in a reservoir are limited by
the lowest known hydrocarbons (LKH) as seen in a well penetration unless geoscience,
engineering, or performance data and reliable technology establishes a lower contact with
reasonable certainty.
 (iii)
    
    Where direct observation from well penetrations has defined a highest known oil (HKO)
elevation and the potential exists for an associated gas cap, proved oil reserves may be
assigned in the structurally higher portions of the reservoir only if geoscience, engineering,
or performance data and reliable technology establish the higher contact with reasonable
certainty.
 (iv)
    
    Reserves which can be produced economically through application of improved recovery
techniques (including, but not limited to, fluid injection) are included in the proved
classification when:
 (A)
    
    Successful testing by a pilot project in an area of the reservoir with
properties no more favorable than in the reservoir as a whole, the operation of an installed
program in the reservoir or an analogous




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DEFINITIONS OF OIL AND GAS RESERVES
 reservoir, or other evidence using reliable technology establishes the reasonable
certainty of the engineering analysis on which the project or program was based; and(B)
    
    The project has been approved for development by all necessary parties and
entities, including governmental entities.
 (v)
    
    Existing economic conditions include prices and costs at which economic producibility from a
reservoir is to be determined. The price shall be the average price during the 12-month period
prior to the ending date of the period covered by the report, determined as an unweighted
arithmetic average of the first-day-of-the-month price for each month within such period, unless
prices are defined by contractual arrangements, excluding escalations based upon future
conditions.
 Proved properties.
 Reasonable certainty.
 Reliable technology.
 Reserves.
 Note to paragraph (a)(26)
 Excerpted from the FASB Accounting Standards Codification Topic 932, Extractive
ActivitiesOil and Gas:
 932-235-50-30 A standardized measure of discounted future net cash flows relating to an entitys
interests in both of the following shall be disclosed as of the end of the year:
 a.
    
    Proved oil
and gas reserves (see paragraphs 932-235-50-3 through 50-11B)b.
    
    Oil and gas subject to
purchase under long-term supply, purchase, or similar agreements and contracts in which the
entity participates in the operation of the properties on which the oil or gas is located or
otherwise serves as the producer of those reserves (see paragraph 932-235-50-7).
 The standardized measure of discounted future net cash flows relating to those two types of
interests in reserves may be combined for reporting purposes.
 932-235-50-31 All of the following information shall be disclosed in the aggregate and for each
geographic area for which reserve quantities are disclosed in accordance with paragraphs
932-235-50-3 through 50-11B:
 a.
    
    Future cash inflows. These shall be computed by applying prices
used in estimating the entitys proved oil and gas reserves to the year-end quantities of those
reserves. Future price changes shall be considered only to the extent provided by contractual
arrangements in existence at year-end.b.
    
    Future development and production costs. These costs
shall be computed by estimating the expenditures to be incurred in developing and producing the
proved oil and gas reserves at the end of the year, based on year-end costs and assuming
continuation of existing economic conditions. If estimated development expenditures are
significant, they shall be presented separately from estimated production costs.c.
    
    Future
income tax expenses. These expenses shall be computed by applying the appropriate year-end
statutory tax rates, with consideration of future tax rates already legislated, to the future
pretax net cash flows relating to the entitys proved oil and gas reserves, less the tax basis
of the properties involved. The future income tax expenses shall give effect to tax deductions
and tax credits and allowances relating to the entitys proved oil and gas reserves.d.
    
    Future
net cash flows. These amounts are the result of subtracting future development and production
costs and future income tax expenses from future cash inflows.




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DEFINITIONS OF OIL AND GAS RESERVES
 e.
    
    Discount. This amount shall be derived from using a discount rate of 10 percent a
year to reflect the timing of the future net cash flows relating to proved oil and gas reserves.f.
    
    Standardized measure of discounted future net cash flows. This amount is the future net cash
flows less the computed discount.
 Reservoir.
 Resources.
 Service well.
 Stratigraphic test well.
 Undeveloped oil and gas reserves.
 (i)
    
    Reserves on undrilled acreage shall be limited to those directly offsetting development
spacing areas that are reasonably certain of production when drilled, unless evidence using
reliable technology exists that establishes reasonable certainty of economic producibility at
greater distances.(ii)
    
    Undrilled locations can be classified as having undeveloped reserves only if a development
plan has been adopted indicating that they are scheduled to be drilled within five years, unless
the specific circumstances, justify a longer time.
 From the SECs Compliance and Disclosure Interpretations (October 26, 2009):
 Although several types of projects  such as constructing offshore platforms and development in
urban areas, remote locations or environmentally sensitive locations  by their nature
customarily take a longer time to develop and therefore often do justify longer time periods,
this determination must always take into consideration all of the facts and circumstances. No
particular type of project per se justifies a longer time period, and any extension beyond five
years should be the exception, and not the rule.
 Factors that a company should consider in determining whether or not circumstances justify
recognizing reserves even though development may extend past five years include, but are not
limited to, the following:
 
    
    The companys level of ongoing significant development activities in the
area to be developed (for example, drilling only the minimum number of wells necessary to
maintain the lease generally would not constitute significant development activities);
    
    The companys historical record at completing development of comparable long-term
projects;
    
    The amount of time in which the company has maintained the leases, or booked the
reserves, without significant development activities;
    
    The extent to which the company has followed a previously adopted development
plan (for example, if a company has changed its development plan several times without taking
significant steps to implement any of those plans, recognizing proved undeveloped reserves
typically would not be appropriate); and
    
    The extent to which delays in development are caused by external factors
related to the physical operating environment (for example, restrictions on development on
Federal lands, but not obtaining government permits), rather than by internal factors (for
example, shifting resources to develop properties with higher priority).(iii)
    
    Under no circumstances shall estimates for undeveloped reserves be attributable to
any acreage for which an application of fluid injection or other improved recovery technique is
contemplated, unless such techniques have been proved effective by actual projects in the same
reservoir or an analogous reservoir, as defined in paragraph (a)(2) of this section, or by other
evidence using reliable technology establishing reasonable certainty.
 Unproved properties.