1
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  Schedule 13D
                               (Amendment No. 1)


                   UNDER THE SECURITIES EXCHANGE ACT OF 1934

                             National-Oilwell, Inc.
- --------------------------------------------------------------------------------
                                (Name of Issuer)

                          Common Stock, $.01 par value
- --------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                   637071 10 1
- --------------------------------------------------------------------------------
                                 (CUSIP Number)

   Thomas R. Denison, First Reserve Corporation, 1801 California Suite 4110,
                        Denver, CO 80202, (303) 382-1270
- --------------------------------------------------------------------------------
           (Name, Address and Telephone Number of Person Authorized to
                      Receive Notices and Communications)

                                    9/30/98
- --------------------------------------------------------------------------------
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this 
schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following 
box / /.

Note: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 13d-7(b) for other
parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
   2
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                         PAGE 2 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    First Reserve Fund V, Limited Partnership
    I.R.S. No.: 06-1295657
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    N/A
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    Delaware
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          334,830
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                                        
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    334,830
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     334,830     
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [X]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     0.6%
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     PN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7 
      (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.

   3
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                         PAGE 3 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    First Reserve Fund V-2, Limited Partnership
    I.R.S. No.: 06-6351960
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    N/A
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    Delaware
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          334,830
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                                        
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    334,830
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     334,830  
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [X]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     0.6%
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     PN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
     (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.  

   4
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                         PAGE 4 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    First Reserve Fund VI, Limited Partnership
    I.R.S. No.: 06-1334650
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    N/A
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    Delaware
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          7,700,834
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                                        
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    7,700,834
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     7,700,834     
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [X]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     14.5%
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     PN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7  
     (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.  

   5
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                         PAGE 5 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    First Reserve Fund VII, Limited Partnership
    I.R.S. No.: 06-1457408
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    OO
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    Delaware
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          1,414,800       
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                                        
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    1,414,800
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,414,800
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [X]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     2.7%
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     PN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7   
     (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.  

   6
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                         PAGE 6 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    First Reserve Fund VIII, LP
    I.R.S. No.: 06-1507364
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    OO
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    Delaware
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          1,414,800       
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                                        
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    1,414,800       
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,414,800            
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [X]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     2.7%    
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     PN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
     (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.  

   7
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                         PAGE 7 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    First Reserve GP VII, LP
    I.R.S. No.: 06-1520256
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    N/A
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    Delaware
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          1,414,800       
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                                        
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    1,414,800       
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,414,800            
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [X]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     2.7%    
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     PN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
     (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.  

   8
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                         PAGE 8 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    First Reserve GP VIII, LP
    I.R.S. No.: 06-1507318
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    N/A
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    Delaware
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          1,414,800     
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                                        
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    1,414,800     
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,414,800          
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [X]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     2.7%    
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     PN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
     (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.  

   9
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                         PAGE 9 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    First Reserve Corporation
    I.R.S. No.: 06-1210123
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    N/A
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    Delaware
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          11,200,094       
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                                        
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    11,200,094       
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     11,200,094            
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [ ]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     21.1%    
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     CO
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7 
     (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.  

   10
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                        PAGE 10 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    William E. Macaulay
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    N/A
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    USA
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           1,333
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          11,200,094       
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                    1,333                    
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    11,200,094       
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     11,201,427            
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [ ]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     21.1%    
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     IN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7   
     (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.  

   11
                                  SCHEDULE 13D

CUSIP NO. 637071 10 1                                        PAGE 11 OF 19 PAGES

- --------------------------------------------------------------------------------
 
1   NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    
    John A. Hill
- --------------------------------------------------------------------------------
2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a) [ ]
                                                                        (b) [X]
- --------------------------------------------------------------------------------
3   SEC USE ONLY


- --------------------------------------------------------------------------------
4   SOURCE OF FUNDS*

    N/A
- --------------------------------------------------------------------------------
5   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 
    TO ITEMS 2(d) OR 2(e)                                                   [ ]

- --------------------------------------------------------------------------------
6   CITIZENSHIP OR PLACE OF ORGANIZATION


    USA
- --------------------------------------------------------------------------------
                7   SOLE VOTING POWER
  NUMBER OF
   SHARES           
BENEFICIALLY   -----------------------------------------------------------------
  OWNED BY      8   SHARED VOTING POWER
   EACH            
 REPORTING          11,200,094       
  PERSON       -----------------------------------------------------------------
   WITH         9   SOLE DISPOSITIVE POWER

                                        
               -----------------------------------------------------------------
               10   SHARED DISPOSITIVE POWER
     
                    11,200,094       
- --------------------------------------------------------------------------------
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     11,200,094            
- --------------------------------------------------------------------------------
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 
     CERTAIN SHARES*                                                        [ ]

- --------------------------------------------------------------------------------
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

     21.1%    
- --------------------------------------------------------------------------------
14   TYPE OF REPORTING PERSON*

     IN
- --------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
         INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
     (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE ATTESTATION.  

   12
         This Amendment No. 1 to the statement on Schedule 13D filed on
September 28, 1998, by First Reserve Fund V, Limited Partnership ("Fund V"),
First Reserve Fund V-2, Limited Partnership ("Fund V-2"), First Reserve Fund VI,
Limited Partnership ("Fund VI"), First Reserve Fund VII, Limited Partnership
("Fund VII"), First Reserve Fund VIII, LP ("Fund VIII", and collectively, with
Fund V, Fund V-2, Fund VI and Fund VII, the "Funds"), First Reserve GP VII, LP,
("GP VII"), First Reserve GP VIII, LP ("GP VIII"), First Reserve Corporation
("First Reserve"), William E. Macaulay and John A. Hill relates to the Common
Stock, par value $0.01 per share (the "Common Stock"), of National-Oilwell, Inc.
a Delaware corporation ("National-Oilwell" or the "Company"). That original
Schedule 13D is hereby supplemented and amended as set forth below.
 
         Item 5 is hereby deleted and replaced with the following:

ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER.

         (a) As of September 30, 1998, the Funds beneficially owned an aggregate
of 11,200,094 shares of Common Stock, constituting approximately 21.1% of the
52,996,785 shares of Common Stock outstanding as of August 12, 1998, as reported
by the Company.

         GP VII and GP VIII as the general partner of Fund VII and Fund VIII,
respectively, may be deemed to beneficially own the shares of Common Stock owned
by those respective Funds. First Reserve as the general partner of Fund V, Fund
V-2, Fund VI, GP VII and GP VIII may be deemed to beneficially own all shares of
Common Stock owned by the Funds. Mr. Macaulay and Mr. Hill may be deemed to
share beneficial ownership of the shares beneficially owned by the Funds as a
result of their ownership of and control over First Reserve. Mr. Macaulay and
Mr. Hill disclaim beneficial ownership of such shares. Except as set forth
otherwise in this Schedule 13D, neither the filing of this Schedule nor any of
its contents shall be deemed to constitute an admission that Mr. Macaulay or Mr.
Hill is the


                                                             PAGE 12 OF 19 PAGES


   13


beneficial owner of the Common Stock referred to in this paragraph for purposes
of Section 13(d) of the Exchange Act or for any other purpose, and such
beneficial ownership is expressly disclaimed.

         The number and percentage of shares of Common Stock beneficially owned
by each Reporting Person are as follows:
Percentage of Shares of Common Stock Outstanding on Shares August 12, 1998 ------ -------------------- Fund V 334,830 .6% Fund V-2 334,830 .6% Fund VI 7,700,834 14.5% Fund VII 1,414,800 2.7% Fund VIII 1,414,800 2.7% GP VII (through Fund VII) 1,414,800 2.7% GP VIII (through Fund VIII) 1,414,800 2.7% First Reserve (through the Funds) 11,200,094 21.1% William E. Macaulay* 11,201,427 21.1% John A. Hill* 11,200,094 21.1%
* 11,200,094 of the shares reported as beneficially owned by Mr. Macaulay and all of the shares reported as beneficially owned by Mr. Hill are directly owned by the Funds. Mr. Macaulay and Mr. Hill disclaim beneficial ownership of such shares. (b) Each Fund shares with its general partner the power to vote or to direct the vote of the shares directly held by it. GP VII and GP VIII, in their roles as general partners of Fund VII and Fund VIII, respectively, and First Reserve, in its role as general partner Fund V, Fund V-2 and Fund VI, and of GP VII and GP VIII, share with each Fund the power to cause each Fund to dispose of PAGE 13 OF 19 PAGES 14 or vote the shares of Common Stock directly held by such Fund. As a result of their positions with and ownership interest in First Reserve, Mr. Macaulay and Mr. Hill may be deemed to have shared power to direct the voting and disposition of all 11,200,094 shares of Common Stock held directly by the Funds. Mr. Macaulay also owns options to purchase 1,333 shares of Common Stock and has sole voting and dispositive power over these shares. (c) The following routine brokerage transactions have been made by the Reporting Persons in the previous 60 days: (1) Purchases by Fund VII:
DOLLAR AMOUNT TRADE DATE SHARES PRICE PER SHARE OF PURCHASE - ---------- ------ --------------- ------------- 9/3/98 25,000 $ 9.0938 $ 227,345.00 9/4/98 12,250 9.25 113,312.50 9/9/98 111,350 10.3660 1,154,254.10 9/10/98 500 10.3125 5,156.25 9/14/98 97,100 12.1250 1,177,337.50 9/15/98 76,950 12.6931 976,734.05 9/17/98 90,800 12.5000 1,135,000.00 9/18/98 ** 250,000 12.4983 3,124,575.00 9/22/98 164,000 11.8415 1,942,006.00
PAGE 14 OF 19 PAGES 15
DOLLAR AMOUNT TRADE DATE SHARES PRICE PER SHARE OF PURCHASE - ---------- ------ --------------- ------------- 9/23/98 72,650 12.2037 886,598.81 9/24/98 78,500 12.0096 942,753.60 9/28/98 208,450 11.2666 2,348,522.77 9/29/98 52,250 12.4847 652,325.58 9/30/98 175,000 12.4440 2,177,700.00 Total Purchases in the past 60 days 1,414,800 16,863,621.15
(2) Purchases by Fund VIII:
DOLLAR AMOUNT TRADE DATE SHARES PRICE PER SHARE OF PURCHASE - ---------- ------ --------------- ------------- 9/3/98 25,000 $ 9.0938 $ 227,345.00 9/4/98 12,250 9.25 113,312.50 9/9/98 111,350 10.3660 1,154,254.10 9/10/98 500 10.3125 5,156.25 9/14/98 97,100 12.1250 1,177,337.50 9/15/98 76,950 12.6931 976,734.05 9/17/98 90,800 12.5000 1,135,000.00 9/18/98 ** 250,000 12.4983 3,124,575.00 9/22/98 164,000 11.8415 1,942,006.00 9/23/98 72,650 12.2037 886,598.81
PAGE 15 OF 19 PAGES 16
DOLLAR AMOUNT TRADE DATE SHARES PRICE PER SHARE OF PURCHASE - ---------- ------ --------------- ------------- 9/24/98 78,500 12.0096 942,753.60 9/28/98 208,450 11.2666 2,348,522.77 9/29/98 52,250 12.4847 652,325.58 9/30/98 175,000 12.4440 2,177,700.00 Total Purchases in the past 60 days 1,414,800 16,863,621.15
** With the transactions on this date the Reporting Persons crossed the 2% threshold for acquisitions within the preceding 12 months and became subject to reporting under Section 13(d) of the Securities and Exchange Act. (d) To the best knowledge of the Reporting Persons, no other person has the right to receive, or the power to direct the receipt of dividends from, or the power to direct the receipt of proceeds of the sale of the shares of Common Stock owned by the Reporting Persons. (e) Not applicable. PAGE 16 OF 19 PAGES 17 SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this Statement is true, complete and correct. Dated: October 1, 1998. FIRST RESERVE FUND V, LIMITED PARTNERSHIP By: First Reserve Corporation, as General Partner By: /s/ THOMAS R. DENISON -------------------------------------- Name: Thomas R. Denison Title: Managing Director FIRST RESERVE FUND V-2, LIMITED PARTNERSHIP By: First Reserve Corporation, as General Partner By: /s/ THOMAS R. DENISON -------------------------------------- Name: Thomas R. Denison Title: Managing Director FIRST RESERVE FUND VI, LIMITED PARTNERSHIP By: First Reserve Corporation, as General Partner By: /s/ THOMAS R. DENISON -------------------------------------- Name: Thomas R. Denison Title: Managing Director PAGE 17 OF 19 PAGES 18 \ FIRST RESERVE FUND VII, LIMITED PARTNERSHIP By: First Reserve GP VII, LP, as General Partner By: First Reserve Corporation, as General Partner By: /s/ THOMAS R. DENISON -------------------------------------- Name: Thomas R. Denison Title: Managing Director FIRST RESERVE FUND VIII, LP By: First Reserve GP VIII, LP, as General Partner By: First Reserve Corporation, as General Partner By: /s/ THOMAS R. DENISON -------------------------------------- Name: Thomas R. Denison Title: Managing Director FIRST RESERVE GP VII, LP By: First Reserve Corporation, as General Partner By: /s/ THOMAS R. DENISON -------------------------------------- Name: Thomas R. Denison Title: Managing Director PAGE 18 OF 19 PAGES 19 FIRST RESERVE GP VIII, LP By: First Reserve Corporation, as General Partner By: /s/ THOMAS R. DENISON -------------------------------------- Name: Thomas R. Denison Title: Managing Director FIRST RESERVE CORPORATION By: /s/ THOMAS R. DENISON ------------------------------------------ Name: Thomas R. Denison Title: Managing Director /s/ WILLIAM E. MACAULAY ------------------------------------------ William E. Macaulay /s/ JOHN A. HILL ------------------------------------------ John A. Hill PAGE 19 OF 19 PAGES