<PAGE>

                                    FORM 10-Q


                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


    [ X ]         QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                              THE SECURITIES EXCHANGE ACT OF 1934

                  For the quarterly period ended June 30, 1998

                                       OR

    [   ]         TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                              THE SECURITIES EXCHANGE ACT OF 1934

        For the transition period from _______________ to ______________

                       Commission File number 33-11773-09


                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
             (Exact name of registrant as specified in its charter)

<TABLE>
<S>                                           <C>       
                  Texas                                    76-0279533
(State or other jurisdiction of organization) (I.R.S. Employer Identification No.)
</TABLE>


                        16825 Northchase Drive, Suite 400
                              Houston, Texas 77060
                    (Address of principal executive offices)
                                   (Zip Code)

                                  (281)874-2700
              (Registrant's telephone number, including area code)

                                      None
              (Former name, former address and former fiscal year,
                          if changed since last report)


Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12 months (or for such  shorter  period that the  Registrant  was
required  to file  such  reports),  and  (2) has  been  subject  to such  filing
requirements for the past 90 days.

                                 Yes  X    No
                                     ---



<PAGE>


                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.

                                      INDEX



<TABLE>
<CAPTION>
PART I.    FINANCIAL INFORMATION                                                    PAGE
      <S>                                                                           <C>
      ITEM 1.    Financial Statements

            Balance Sheets

                - June 30, 1998 and December 31, 1997                                3

            Statements of Operations

                - Three month and six month periods ended June 30, 1998 and 1997     4

            Statements of Cash Flows

                - Six month periods ended June 30, 1998 and 1997                     5

            Notes to Financial Statements                                            6

      ITEM 2.    Management's Discussion and Analysis of Financial
                     Condition and Results of Operations                             9

PART II.    OTHER INFORMATION                                                       11


SIGNATURES                                                                          12
</TABLE>


<PAGE>

                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
                                 BALANCE SHEETS



<TABLE>
<CAPTION>
                                                                                          June 30,           December 31,
                                                                                            1998                 1997
                                                                                       ---------------     ----------------
                                                                                        (Unaudited)
         <S>                                                                           <C>                  <C>           
         ASSETS:

         Current Assets:
              Cash and cash equivalents                                                $       68,933       $      390,534
              Oil and gas sales receivable                                                    283,947              402,035
                                                                                       ---------------     ----------------
                  Total Current Assets                                                        352,880              792,569
                                                                                       ---------------     ----------------

         Gas Imbalance Receivable                                                              91,836               93,964
                                                                                       ---------------     ----------------

         Oil and Gas Properties, using full cost
              accounting                                                                    8,646,695            8,517,702
         Less-Accumulated depreciation, depletion
              and amortization                                                             (5,743,750)          (5,532,503)
                                                                                       ---------------     ----------------
                                                                                            2,902,945            2,985,199
                                                                                       ---------------     ----------------
                                                                                       $    3,347,661       $    3,871,732
                                                                                       ===============     ================


         LIABILITIES AND PARTNERS' CAPITAL:

         Current Liabilities:
              Accounts Payable                                                         $      115,781       $      138,407
                                                                                       ---------------     ----------------

         Deferred Revenues                                                                     56,721               59,718

         Limited Partners' Capital (83,295 Limited Partnership Units;
                                   $100 per unit)                                           3,137,120            3,623,998
         General Partners' Capital                                                             38,039               49,609
                                                                                       ---------------     ----------------
                  Total Partners' Capital                                                   3,175,159            3,673,607
                                                                                       ---------------     ----------------
                                                                                       $    3,347,661       $    3,871,732
                                                                                       ===============     ================
</TABLE>


                 See accompanying notes to financial statements.

                                        3


<PAGE>

                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
                            STATEMENTS OF OPERATIONS
                                   (Unaudited)




<TABLE>
<CAPTION>
                                                     Three Months Ended                  Six Months Ended
                                                          June 30,                           June 30,
                                              ---------------------------------  ---------------------------------
                                                   1998              1997             1998              1997
                                              ---------------   ---------------  ---------------   ---------------
<S>                                           <C>               <C>              <C>               <C>            
REVENUES:
   Oil and gas sales                          $       255,887   $       329,268  $       519,797   $       840,096
   Interest income                                      1,502             6,719            4,581            12,004
   Other                                                1,680             1,945            3,077             4,665
                                              ---------------   ---------------  ---------------   ---------------
                                                      259,069           337,932          527,455           856,765
                                              ---------------   ---------------  ---------------   ---------------

COSTS AND EXPENSES:
   Lease operating                                     84,834           123,463          168,026           222,488
   Production taxes                                    14,421            16,422           28,184            43,090
   Depreciation, depletion
      and amortization                                103,565           105,254          211,247           231,635
   General and administrative                          37,254            45,739           70,755            95,878
                                              ---------------   ---------------  ---------------   ---------------
                                                      240,074           290,878          478,212           593,091
                                              ---------------   ---------------  ---------------   ---------------
NET INCOME (LOSS)                             $        18,995   $        47,054  $        49,243   $       263,674
                                              ===============   ===============  ===============   ===============




Limited Partners' net income (loss)
   per unit                                   $           .23   $           .56  $           .59   $          3.17
                                              ===============   ===============  ===============   ===============
</TABLE>


                 See accompanying notes to financial statements.

                                        4

<PAGE>


                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)

<TABLE>
<CAPTION>
                                                                                            Six Months Ended
                                                                                                June 30,
                                                                               ----------------------------------------
                                                                                     1998                    1997
                                                                               ---------------          ---------------
<S>                                                                             <C>                     <C>            
CASH FLOWS FROM OPERATING ACTIVITIES:
    Income (loss)                                                               $       49,243          $       263,674
    Adjustments to reconcile income (loss) to
      net cash provided by operations:
      Depreciation, depletion and amortization                                         211,247                  231,635
      Change in gas imbalance receivable
          and deferred revenues                                                           (869)                  18,554
      Change in assets and liabilities:
        (Increase) decrease in oil and gas sales receivable                            118,088                  280,537
        (Increase) decrease in other current assets                                         --                   (7,270)
        Increase (decrease) in accounts payable                                        (22,626)                (186,871)
                                                                               ---------------          ---------------
      Net cash provided by (used in) operating activities                              355,083                  600,259
                                                                               ---------------          ---------------
CASH FLOWS FROM INVESTING ACTIVITIES:
    Additions to oil and gas properties                                               (128,993)                 (56,212)
    Proceeds from sales of oil and gas properties                                           --                    4,336
    (Increase) decrease in receivable due to property disposition                           --                  120,429
                                                                               ---------------          ---------------
      Net cash provided by (used in) investing activities                             (128,993)                  68,553
                                                                               ---------------          ---------------
CASH FLOWS FROM FINANCING ACTIVITIES:
    Cash distributions to partners                                                    (547,691)                (630,562)
                                                                               ---------------          ---------------
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS                                  (321,601)                  38,250
                                                                               ---------------          ---------------
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD                                       390,534                  497,687
                                                                               ---------------          ---------------
CASH AND CASH EQUIVALENTS AT END OF PERIOD                                      $       68,933          $       535,937
                                                                               ===============          ===============
</TABLE>


                 See accompanying notes to financial statements.

                                        5


<PAGE>

                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
                          NOTES TO FINANCIAL STATEMENTS
                                   (UNAUDITED)


(1)  General Information -

                  The financial statements included herein have been prepared by
        the  Partnership  and are  unaudited  except  for the  balance  sheet at
        December  31,  1997  which has been  taken  from the  audited  financial
        statements at that date. The financial  statements reflect  adjustments,
        all of which  were of a  normal  recurring  nature,  which  are,  in the
        opinion  of  the  managing   general   partner   necessary  for  a  fair
        presentation.  Certain  information  and footnote  disclosures  normally
        included in financial  statements  prepared in accordance with generally
        accepted  accounting  principles have been omitted pursuant to the rules
        and regulations of the Securities and Exchange Commission  ("SEC").  The
        Partnership  believes adequate disclosure is provided by the information
        presented.  The financial  statements should be read in conjunction with
        the audited  financial  statements  and the notes included in the latest
        Form 10-K.

(2)  Organization and Terms of Partnership Agreement -

                  Swift Energy  Income  Partners  1989-B,  Ltd., a Texas limited
        partnership  ("the  Partnership"),  was formed on June 30, 1989, for the
        purpose of  purchasing  and operating  producing oil and gas  properties
        within the continental United States. Swift Energy Company ("Swift"),  a
        Texas   corporation,   and  VJM   Corporation   ("VJM"),   a  California
        corporation,  serve as Managing  General  Partner  and  Special  General
        Partner of the  Partnership,  respectively.  The  general  partners  are
        required   to   contribute   up  to  1/99th  of  limited   partner   net
        contributions. The 661 limited partners made total capital contributions
        of $8,329,500.

                  Property acquisition costs and the management fee are borne 99
        percent by the limited partners and one percent by the general partners.
        Organization  and  syndication  costs were borne  solely by the  limited
        partners.

                  Generally,  all continuing costs (including development costs,
        operating costs,  general and  administrative  reimbursements and direct
        expenses) and revenues are allocated 90 percent to the limited  partners
        and ten percent to the general partners. If prior to partnership payout,
        however,  the cash  distribution  rate for a  certain  period  equals or
        exceeds  17.5  percent,  then for the  following  calendar  year,  these
        continuing  costs and  revenues  will be  allocated  85  percent  to the
        limited  partners  and  15  percent  to  the  general  partners.   After
        partnership  payout,  continuing  costs and  revenues  will be shared 85
        percent by the limited partners, and 15 percent by the general partners,
        even if the cash  distribution  rate is less than 17.5  percent.  During
        1992 and 1991, the cash distribution rate (as defined in the Partnership
        Agreement)  exceeded  17.5  percent  and  thus,  in 1993 and  1992,  the
        continuing  costs and  revenues  were  shared 85 percent by the  limited
        partners  and 15 percent by the general  partners.  During  1997,  1996,
        1995, 1994 and 1993, the cash  distribution rate fell below 17.5 percent
        and  thus,  in 1997,  1996,  1995 and  1994,  the  continuing  costs and
        revenues  were shared 90 percent by the limited  partners and 10 percent
        by the general partners. Payout occurred in January 1998; therefore, for
        1998  and  each  year  remaining  in the  life of the  partnership,  the
        continuing  costs and revenues  will be shared 85 percent by the limited
        partners and 15 percent by the general partners.

(3)  Significant Accounting Policies -

      Use of Estimates --

                  The  preparation  of financial  statements in conformity  with
        generally accepted  accounting  principles  requires  management to make
        estimates and assumptions that affect the reported amounts of assets and
        liabilities  at the date of the  financial  statements  and the reported
        amounts of revenues and expenses  during the  reporting  period.  Actual
        results could differ from estimates.

                                       6

<PAGE>


                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)
                                   (UNAUDITED)


Oil and Gas Properties --

                  The Partnership accounts for its ownership interest in oil and
        gas properties using the proportionate consolidation method, whereby the
        Partnership's  share of assets,  liabilities,  revenues  and expenses is
        included in the appropriate classification in the financial statement.

                  For financial  reporting purposes the Partnership  follows the
        "full-cost"  method of accounting for oil and gas property costs.  Under
        this  method of  accounting,  all  productive  and  nonproductive  costs
        incurred in the  acquisition and development of oil and gas reserves are
        capitalized.  Such costs  include  lease  acquisitions,  geological  and
        geophysical  services,  drilling,  completion,   equipment  and  certain
        general and  administrative  costs directly  associated with acquisition
        and development activities.  General and administrative costs related to
        production and general overhead are expensed as incurred. No general and
        administrative  costs were capitalized  during the six months ended June
        30, 1998 and 1997.

                  Future  development,   site  restoration,   dismantlement  and
        abandonment   costs,   net  of  salvage  values,   are  estimated  on  a
        property-by-property  basis based on current economic conditions and are
        amortized  to  expense  as the  Partnership's  capitalized  oil  and gas
        property costs are amortized.

                  The  unamortized  cost of oil and gas properties is limited to
        the "ceiling  limitation"  (calculated  separately for the  Partnership,
        limited  partners and general  partners).  The "ceiling  limitation"  is
        calculated on a quarterly basis and represents the estimated  future net
        revenues from proved properties using current prices,  discounted at ten
        percent,  and the lower of cost or fair  value of  unproved  properties.
        Proceeds  from the sale or  disposition  of oil and gas  properties  are
        treated as a reduction  of oil and gas  property  costs with no gains or
        losses being recognized except in significant transactions.

                  The  Partnership  computes  the  provision  for  depreciation,
        depletion   and   amortization   of  oil  and  gas   properties  on  the
        units-of-production   method.   Under  this  method,  the  provision  is
        calculated  by  multiplying  the total  unamortized  cost of oil and gas
        properties,    including   future    development,    site   restoration,
        dismantlement  and abandonment  costs, by an overall  amortization  rate
        that  is  determined  by  dividing  the  physical  units  of oil and gas
        produced  during the period by the total  estimated  units of proved oil
        and gas reserves at the beginning of the period.

                  The calculation of the "ceiling  limitation" and the provision
        for  depreciation,  depletion and  amortization is based on estimates of
        proved reserves. There are numerous uncertainties inherent in estimating
        quantities  of proved  reserves  and in  projecting  the future rates of
        production,  timing and plan of development. The accuracy of any reserve
        estimate  is a  function  of  the  quality  of  available  data  and  of
        engineering  and  geological  interpretation  and  judgment.  Results of
        drilling,  testing and production subsequent to the date of the estimate
        may justify revision of such estimate.  Accordingly,  reserve  estimates
        are  often  different  from  the  quantities  of oil  and gas  that  are
        ultimately recovered.

(4)  Related-Party Transactions -

                  An  affiliate  of  the  Special  General  Partner,  as  Dealer
        Manager,  received  $202,238 for managing and overseeing the offering of
        the limited partnership units. A one-time management fee of $208,238 was
        paid to Swift for services performed for the Partnership.

                                       7
<PAGE>


                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)
                                   (UNAUDITED)


                  Effective  June 30, 1989, the  Partnership  entered into a Net
        Profits and Overriding  Royalty Interest  Agreement ("NP/OR  Agreement")
        with Swift  Energy  Managed  Pension  Assets  Partnership  1989-B,  Ltd.
        ("Pension  Partnership"),  managed by Swift for the purpose of acquiring
        working  interests in producing oil and gas  properties.  Under terms of
        the  NP/OR  Agreement,  the  Partnership  will  convey  to  the  Pension
        Partnership a nonoperating  interest in the aggregate net profits (i.e.,
        oil and gas  sales net of  related  operating  costs) of the  properties
        acquired equal to its  proportionate  share of the property  acquisition
        costs.

(5)  Gas Imbalances -

                  The Partnership  recognizes its ownership  interest in natural
        gas  production as revenue.  Actual  production  quantities  sold may be
        different than the  Partnership's  ownership share in a given period. If
        the  Partnership's  sales exceed its ownership share of production,  the
        differences are recorded as deferred revenue. Gas balancing  receivables
        are  recorded  when the  Partnership's  ownership  share  of  production
        exceeds sales.

(6)  Vulnerability Due to Certain Concentrations -

                  The  Partnership's  revenues are primarily the result of sales
        of its oil and natural gas production.  Market prices of oil and natural
        gas may fluctuate and adversely affect operating results.

                  In the normal  course of  business,  the  Partnership  extends
        credit,  primarily in the form of monthly oil and gas sales receivables,
        to various  companies  in the oil and gas  industry  which  results in a
        concentration  of credit risk. This  concentration of credit risk may be
        affected by changes in economic or other  conditions and may accordingly
        impact the  Partnership's  overall  credit risk.  However,  the Managing
        General  Partner  believes  that  the  risk is  mitigated  by the  size,
        reputation, and nature of the companies to which the Partnership extends
        credit.  In  addition,   the  Partnership  generally  does  not  require
        collateral or other security to support customer  receivables.  (7) Fair
        Value of Financial Instruments -

                  The Partnership's  financial  instruments  consist of cash and
        cash equivalents and short-term  receivables and payables.  The carrying
        amounts  approximate  fair value due to the highly  liquid nature of the
        short-term instruments.

                                       8

<PAGE>

                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
                MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                       CONDITION AND RESULTS OF OPERATIONS


GENERAL

      The  Partnership  was formed for the purpose of investing in producing oil
and gas properties  located within the  continental  United States.  In order to
accomplish  this,  the  Partnership  goes through two  distinct yet  overlapping
phases  with  respect  to its  liquidity  and  result  of  operations.  When the
Partnership  is formed,  it commences its  "acquisition"  phase,  with all funds
placed in short-term  investments until required for such property acquisitions.
The interest  earned on these  pre-acquisition  investments  becomes the primary
cash flow source for initial partner distributions.  As the Partnership acquires
producing   properties,   net  cash  from  operations   becomes   available  for
distribution,  along with the investment  income.  After  partnership funds have
been expended on producing oil and gas properties,  the  Partnership  enters its
"operations" phase. During this phase, oil and gas sales generate  substantially
all revenues,  and  distributions  to partners  reflect those  revenues less all
associated  partnership expenses.  The Partnership may also derive proceeds from
the sale of acquired oil and gas properties, when the sale of such properties is
economically appropriate or preferable to continued operation.

LIQUIDITY AND CAPITAL RESOURCES

      Oil and gas reserves are depleting  assets and therefore often  experience
significant  production  declines each year from the date of acquisition through
the end of the life of the  property.  The primary  source of  liquidity  to the
Partnership comes almost entirely from the income generated from the sale of oil
and gas produced from ownership  interests in oil and gas  properties.  Net cash
provided by  operating  activities  totaled  $355,083  and  $600,259 for the six
months ended June 30, 1998 and 1997, respectively.  This source of liquidity and
the related results of operations, and in turn cash distributions,  will decline
in  future  periods  as the oil and gas  produced  from  these  properties  also
declines while production and general and administrative costs remain relatively
stable making it unlikely that the  Partnership  will hold the properties  until
they are fully depleted,  but will likely liquidate when a substantial  majority
of the reserves  have been  produced.  The  Partnership  has expended all of the
partners' net commitments available for property acquisitions and development by
acquiring producing oil and gas properties. The partnership invests primarily in
proved  producing  properties with nominal levels of future costs of development
for  proven  but  undeveloped  reserves.  Significant  purchases  of  additional
reserves or extensive drilling activity are not anticipated.  Cash distributions
totaled  $547,691  and $630,562 for the six months ended June 30, 1998 and 1997,
respectively.

      The  Partnership  does  not  allow  for  additional  assessments  from the
partners  to fund  capital  requirements.  However,  funds  are  available  from
partnership  revenues,  borrowings  or  proceeds  from the  sale of  partnership
property.  The  Managing  General  Partners  believes  that the funds  currently
available to the partnership  will be adequate to meet any  anticipated  capital
requirements.

RESULTS OF OPERATIONS

      The  following  analysis  explains  changes  in the  revenue  and  expense
categories  for the quarter ended June 30, 1998 (current  quarter) when compared
to the quarter  ended June 30,  1997  (corresponding  quarter),  and for the six
months ended June 30, 1998  (current  period),  when  compared to the six months
ended June 30, 1997 (corresponding period).

Three Months Ended June 30, 1998 and 1997

      Oil and gas sales declined  $73,381 or 22 percent in the second quarter of
1998 when  compared  to the  corresponding  quarter  in 1997,  primarily  due to
decreased  oil prices.  A decline in oil prices of 33 percent or $5.71/BBL had a
significant  impact  on  partnership  performance.  Also,  current  quarter  oil
production  declined 28 percent when compared to second quarter 1997  production
volumes.  The partnership's  sale of several properties in 1997 had an impact on
1998 partnership production volumes.

                                       9

<PAGE>


                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
                MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                 CONDITION AND RESULTS OF OPERATIONS (CONTINUED)


      Associated  depreciation  expense  decreased  2 percent  or $1,689 in 1998
compared to second  quarter  1997,  also  related to the  decline in  production
volumes.

Six Months Ended June 30, 1998 and 1997

      Oil and gas sales declined  $320,299 or 38 percent in the first six months
of 1998 when  compared to the  corresponding  period in 1997,  primarily  due to
decreased oil and gas prices. A decline in oil prices of 37 percent or $6.82/BBL
and in gas  prices  of 21  percent  or  $.58/MCF  had a  significant  impact  on
partnership performance. Also, current period oil and gas production declined 20
percent and 6 percent,  respectively,  when compared to the same period in 1997,
further  contributing to decreased  revenues.  The partnership's sale of several
properties in 1997 had an impact on 1998 partnership production volumes.

      Associated  depreciation  expense  decreased  9 percent or $20,388 in 1998
compared  to the first six  months  of 1997,  also  related  to the  decline  in
production volumes.

      During 1998,  partnership  revenues  and costs will be shared  between the
limited partners and general partners in a 85:15 ratio.


                                       10


<PAGE>


                    SWIFT ENERGY INCOME PARTNERS 1989-B, LTD.
                           PART II - OTHER INFORMATION




ITEM 5.    OTHER INFORMATION


                                     -NONE-



                                       11


<PAGE>


                                   SIGNATURES



Pursuant to the  requirements of Section 13 or 15(d) of the Securities  Exchange
Act of 1934,  the  Registrant  has duly  caused  this report to be signed on its
behalf by the undersigned thereunto duly authorized.


                                         SWIFT ENERGY INCOME
                                         PARTNERS 1989-B, LTD.
                                         (Registrant)

                              By:        SWIFT ENERGY COMPANY
                                         Managing General Partner

Date:     August 4, 1998      By:        /s/ John R. Alden
          --------------                 --------------------------------
                                         John R. Alden
                                         Senior Vice President, Secretary
                                         and Principal Financial Officer

Date:     August 4, 1998      By:        /s/ Alton D. Heckaman, Jr.
          --------------                 --------------------------------
                                         Alton D. Heckaman, Jr.
                                         Vice President, Controller
                                         and Principal Accounting Officer


                                       12