<ARTICLE>                     5
<LEGEND>
This schedule contains summary financial information extracted from Swift Energy
Managed Pension Assets Partnership 1989-B, Ltd.'s balance sheet and statement of
operations  contained in its Form 10-K for the year ended  December 31, 1997 and
is qualified in its entirety by reference to such financial statements.
</LEGEND>
       
                             
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                              DEC-31-1997
<PERIOD-END>                                   DEC-31-1997
<CASH>                                         67,645
<SECURITIES>                                   0
<RECEIVABLES>                                  143,694
<ALLOWANCES>                                   0
<INVENTORY>                                    0
<CURRENT-ASSETS>                               211,339
<PP&E>                                         3,823,672
<DEPRECIATION>                                 (2,430,419)
<TOTAL-ASSETS>                                 1,604,592
<CURRENT-LIABILITIES>                          5,379
<BONDS>                                        0
<PREFERRED-MANDATORY>                          0
<PREFERRED>                                    0
<COMMON>                                       0
<OTHER-SE>                                     1,599,213
<TOTAL-LIABILITY-AND-EQUITY>                   1,604,592
<SALES>                                        521,108
<TOTAL-REVENUES>                               526,455
<CGS>                                          0
<TOTAL-COSTS>                                  211,059<F1>
<OTHER-EXPENSES>                               0
<LOSS-PROVISION>                               0
<INTEREST-EXPENSE>                             0
<INCOME-PRETAX>                                239,347
<INCOME-TAX>                                   0
<INCOME-CONTINUING>                            239,347
<DISCONTINUED>                                 0
<EXTRAORDINARY>                                0
<CHANGES>                                      0
<NET-INCOME>                                   239,347
<EPS-PRIMARY>                                  0
<EPS-DILUTED>                                  0
<FN>
<F1>Includes  lease  operating  expenses,  production  taxes  and  depreciation,
depletion and  amortization  expense.  Excludes general and  administrative  and
interest expense.
</FN>