<PAGE>
     
subject to approval by the Board of Directors of the Company. Schroder Wertheim
did not recommend to the Company or Weatherford Enterra the consideration to be
paid by Weatherford Enterra.     
 
  The full text of the written opinion of Schroder Wertheim dated September 20,
1995, which sets forth the assumptions made, factors considered and limitations
on the review undertaken by Schroder Wertheim, is included as Appendix B to
this Proxy Statement. The following is a summary of the analysis conducted by
Schroder Wertheim as the basis for its fairness opinion which was presented
orally to the Company's Board of Directors on September 20, 1995, and
subsequently confirmed in writing, to the effect that, as of such date, the
consideration to be received by the Company pursuant to the Purchase Agreement,
is fair, from a financial point of view, to the Company. This summary does not
purport to be a complete description of the analyses performed by Schroder
Wertheim in this regard but does provide an overview of the material analyses
conducted by Schroder Wertheim. Schroder Wertheim's opinion is directed only to
the consideration to be received by the Company pursuant to the Purchase
Agreement and does not constitute a recommendation to any stockholder of the
Company as to how such stockholder should vote regarding the Energy Industries
Sale Proposal. The summary is qualified in its entirety by reference to the
full text of such opinion. Stockholders are encouraged to read the opinion in
its entirety.
     
  Schroder Wertheim is not obligated to update the fairness opinion and the
Company does not currently intend to request Schroder Wertheim to do so.     
 
  Review of Energy Industries' Recent and Pro Forma Projected Financial
Information. Schroder Wertheim reviewed the historical and pro forma financial
information of Energy Industries for various periods and management's projected
financial performance for the fiscal years ended September 30, 1995 and 1996.
In its review, Schroder Wertheim noted that results for the eleven months and
latest twelve months ("LTM") ended August 31, 1995 and the projected results
for the fiscal year ended September 30, 1995 reflect actual and expected
declines in financial performance as compared to comparable prior year periods.
Schroder Wertheim further noted that Energy Industries reported earnings before
interest, taxes, depreciation and amortization ("EBITDA") of $13.2 million for
the fiscal year ended September 30, 1994, $12.7 million for the LTM ended
August 31, 1995 and projected EBITDA of $12.2 million and $14.3 million for the
fiscal years ended September 30, 1995 and 1996, respectively.
     
  Analysis of Comparable Recent Acquisition Transactions. Schroder Wertheim
reviewed the financial terms, to the extent publicly available, of certain
recent acquisition transactions which Schroder Wertheim deemed to be reasonably
comparable to the proposed Energy Industries Sale. In performing its analysis,
Schroder Wertheim compared selected financial data, including Adjusted Purchase
Price (the equity cost plus latest reported total debt, capitalized leases,
preferred stock and minority interests, minus total cash and cash equivalents)
or asset purchase price, as appropriate, as a multiple of LTM earnings before
interest and taxes ("EBIT"), EBITDA and tangible book value of assets for
selected recent natural gas compression industry sale transactions involving
the sale of businesses which were direct comparables to Energy Industries based
on similar operations. The selected transactions included all of the five
significant sales transactions which have occurred since late 1993 for which
information was available: (i) the Company's purchase of Energy Industries,
(ii) Enterra Corporation's acquisition of Total Energy Services Company, (iii)
Tidewater Inc.'s acquisition of Brazos Gas Compressing Company, (iv) Tidewater
Inc.'s acquisition of Haliburton Compression Services, and (v) Global
Compression Services, Inc.'s acquisition of Total Compression, Inc. Schroder
Wertheim's analysis indicated estimated mean LTM EBIT and LTM EBITDA multiples
for the comparable transactions of approximately 13.8x and 8.5x, respectively,
versus approximately 18.5x and 9.9x, respectively, for Energy Industries under
the proposed terms of the Energy Industries Sale Proposal. Schroder Wertheim
noted that the multiple of tangible book value of assets was below the range;
however, this fact was determined to be attributable to (i) the relatively high
book value of Energy Industries' fixed assets due to the step-up in book value
of Energy Industries pursuant to the purchase accounting relating to the
Company's acquisition of Energy Industries in November 1993, and (ii) Energy
Industries' management's strategy of maintaining relatively large inventory
balances.     
 
 
                                       8