actual results could differ from those estimates . significant estimates with regard to these financial statements include estimates of remaining proved natural gas and oil reserves , the timing and costs of our future drilling , development and abandonment activities , and income taxes . see “ item 1a . risk factors ” for a more detailed discussion of a number of other factors that affect our business , financial condition and results of operations . 52 going concern assessment as discussed below under “ capital resources and liquidity , ” our credit facility ( as defined below ) currently matures on october 1 , 2019. over the past few months , we have been in discussions with our current lenders and other sources of capital regarding a possible refinancing and or replacement of our existing credit facility . there is no assurance , however , that such discussions will result in a refinancing of the credit facility on acceptable terms , if at all , or provide any specific amount of additional liquidity for future capital expenditures . these conditions raise substantial doubt about our ability to continue as a going concern . however , the accompanying financial statements have been prepared assuming we will continue to operate as a going concern , which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business . the accompanying financial statements do not include adjustments that might result from the outcome of the uncertainty , including any adjustments to reflect the possible future effects of the recoverability and classification of recorded asset amounts or amounts and classifications of liabilities that might be necessary should we be unable to continue as a going concern . as discussed below under “ capital resources and liquidity , ” management is evaluating plans to refinance and or replace the credit facility . results of operations the table below sets forth our average net daily production data in mmcfe/d from our fields for each of the periods indicated : replace_table_token_22_th ( 1 ) includes a decreased production rate of 4.2 mmcfe/d due to downtime related to compressor installation and maintenance during the three months ended june 30 , 2018. our gom production was not materially affected by hurricane michael which passed through the northeastern gom in october 2018 . ( 2 ) includes a decreased production rate of 0.8 mmcfe/d due to temporary pipeline limitations during the three months ended june 30 , 2017 and 0.5 mmcfe/d for the three months ended december 31 , 2018 . ( 3 ) south timbalier 17 ceased production in august 2017 . ( 4 ) includes woodbine production from madison and grimes counties and conventional production in others . decrease in production during three months ended december 31 , 2018 is primarily due to the liberty and hardin county property sale in november 2018 . ( 5 ) includes eagle ford and buda production from karnes , zavala and dimmit counties , and conventional production in others , prior to june 30 , 2018. does not include karnes county in the three months ended june 30 , 2018 and forward due to its sale in march 2018 . ( 6 ) includes onshore wells primarily in east texas and wyoming . 53 year ended december 31 , 2018 compared to year ended december 31 , 2017 the table below sets forth revenue , production data , average sales prices and average production costs associated with our sales of natural gas , oil and natural gas liquids ( `` ngls `` ) from continuing operations for the years ended december 31 , 2018 and 2017. oil , condensate and ngls are compared with natural gas in terms of cubic feet of natural gas equivalents . one barrel of oil , condensate or ngl is the energy equivalent of six mcf of natural gas . reported operating expenses include production taxes , such as ad valorem and severance . replace_table_token_23_th 54 replace_table_token_24_th 55 natural gas , oil and ngl sales and production all of our revenues are from the sale of our natural gas , crude oil and natural gas liquids production . our revenues may vary significantly from year to year depending on changes in commodity prices , which fluctuate widely , and production volumes . our production volumes are subject to wide swings as a result of new discoveries , weather and mechanical related problems . in addition , the production rate associated with our oil and gas properties declines over time as we produce our reserves . we reported revenues of approximately $ 77.1 million for the year ended december 31 , 2018 , compared to revenues of approximately $ 78.5 million for the year ended december 31 , 2017. this slight decrease in revenues was primarily due to a reduction in natural gas production attributable to 2018 non-core property sales , the expected year over year decline in our offshore properties and the reduction in our fourth quarter 2018 drilling program in response to declining oil prices ; declines which were substantially offset by the benefit of higher commodity prices in 2018. total production for the year ended december 31 , 2018 was approximately 16.0 bcfe , or 43.9 mmcfe/d , compared to approximately 20.1 bcfe , or 55.1 mmcfe/d , in the prior year . the decrease was attributable to an approximate 13 mmcfe/d decline in production resulting from normal field decline , an approximate 2 mmcfe/d decline due to non-core property sales , and an approximate 1 mmcfe/d decline due to shut-in periods at eugene island for compressor installation in june . partially offsetting these decreases in production was an increase of approximately 4 mmcfe/d of new production ( 88 % oil and ngls ) from drilling on our southern delaware basin acreage . story_separator_special_tag holding all other factors constant , a reduction in the company 's proved reserve estimate at december 31 , 2018 of 5 % , 10 % and 15 % would affect depreciation , depletion and amortization expense by approximately $ 0.4 million , $ 0.9 million and $ 1.4 million , respectively . impairment of natural gas and oil properties the company reviews its proved natural gas and oil properties for impairment whenever events and circumstances indicate a potential decline in the recoverability of their carrying value . an impairment loss associated with an asset group is the amount by which the carrying amount of a long-lived asset is not recoverable and exceeds its fair value . an asset 's fair value is preferably indicated by a quoted market price in the asset 's principal market . unlike many businesses where independent appraisals can be obtained for items such as equipment , oil and gas proved reserves are unique assets . most oil and gas valuations are based on a combination of the income approach and market approach methodologies . we utilize the income approach also known as the discounted cash flow ( “ dcf ” ) approach . under the dcf method in determining fair value , there are specific guidelines and ranges within the evaluation that we can consider and estimate . the company compares expected undiscounted future net cash flows from each field to the unamortized capitalized cost of the asset . if the future undiscounted net cash flows , based on the company 's estimate of future natural gas and oil prices and operating costs and anticipated production from proved reserves , are lower than the unamortized capitalized cost , then the capitalized cost is reduced to fair market value . the factors used to determine fair value include , but are not limited to , estimates of reserves , future commodity pricing , future production estimates and anticipated capital expenditures . unproved properties are reviewed quarterly to determine if there has been impairment of the carrying value , with any such impairment charged to expense in the period . drilling activities in an area by other companies may also effectively impair leasehold positions . given the complexities associated with natural gas and oil reserve estimates and the history of price volatility in the natural gas and oil markets , events may arise that will require the company to record an impairment of its natural gas and oil properties and there can be no assurance that such impairments will not be required in the future nor that they will not be material . assuming strip pricing as of march 1 , 2019 through 2023 and keeping pricing flat thereafter , instead of 2018 sec pricing , while leaving all other parameters unchanged , the company 's proved reserves would have been 84.8 bcfe and the pv-10 value of proved reserves would have been $ 145.4 million . 61 derivative instruments the company elected to not designate any of its derivative positions for hedge accounting at the end of each reporting period we record on our balance sheet the mark-to-market valuation of our derivative instruments . the estimated change in fair value of the derivatives , along with the realized gain or loss for settled derivatives , is reported in “ other income ( expense ) ” as “ gain on derivatives , net ” . income taxes income taxes are provided for the tax effects of transactions reported in the financial statements and consist of taxes currently payable plus deferred income taxes related to certain income and expenses recognized in different periods for financial and income tax reporting purposes . deferred income taxes are measured by applying currently enacted tax rates to the differences between financial statements and income tax reporting . numerous judgments and assumptions are inherent in the determination of deferred income tax assets and liabilities as well as income taxes payable in the current period . we are subject to taxation in several jurisdictions , and the calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations in various taxing jurisdictions . accounting for uncertainty in income taxes prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of income tax positions taken or expected to be taken in an income tax return . for those benefits to be recognized , an income tax position must be more-likely-than-not to be sustained upon examination by taxing authorities . in assessing the realizability of deferred tax assets , we consider whether it is more likely than not that some portion or all of the deferred tax assets will not be realized . as of december 31 , 2018 , we had federal net operating loss ( “ nol ” ) carryforwards of $ 380.8 million . generally , these nols are available to reduce future taxable income and the related income tax liability subject to the limitations set forth in section 382. however , these nols are subject to an annual section 382 limitation as a result of the ownership change that occurred in connection with our stock offering in november 2018. given our annual section 382 limitation and the uncertainty of our ability to generate taxable income , a valuation allowance of $ 71.0 million has been recorded for the year ended december 31 , 2018 against the deferred tax assets , reduced by the amount of the deferred tax liability . our federal and state income tax returns are generally not filed before the consolidated financial statements are prepared . therefore , we estimate the tax basis of our assets and liabilities at the end of each period as well as the effects of tax rate changes , tax credits and net operating and capital loss carryforwards and carrybacks . adjustments related to differences between the estimates we used and actual amounts we reported are recorded in the period in

capital resources and liquidity our primary cash requirements are for capital expenditures , working capital , operating expenses , acquisitions and principal and interest payments on indebtedness . our primary sources of liquidity are cash generated by operations , net of the realized effect of our hedging agreements , and amounts available to be drawn under our credit facility . the table below summarizes certain measures of liquidity and capital expenditures , as well as our sources of capital from internal and external sources , for the periods indicated , in thousands . replace_table_token_26_th cash flow from operating activities , including changes in working capital , provided approximately $ 23.5 million in cash for the year ended december 31 , 2018 compared to $ 34.7 million for the year ended december 31 , 2017. cash flow from operating activities , excluding changes in working capital , provided approximately $ 22.1 million in cash for the year ended december 31 , 2018 compared to $ 29.6 million for the year ended december 31 , 2017. cash provided due to changes in working capital were approximately $ 1.4 million during 2018 , compared to $ 5.1 million during 2017 and represent normal receivable and payable activity during the period . net cash flows used in investing activities were $ 30.7 million for the year ended december 31 , 2018. we expended $ 59.0 million in cash capital costs , primarily related to drilling and or completing wells in the southern delaware basin and acquiring or extending unproved leases , partially offset by $ 27.8 million in cash proceeds from the sale of our non-core properties . net cash flows used in investing activities were $ 65.5 million for the year ended december 31 , 2017. we expended $ 66.6 million in cash capital costs , primarily related to drilling and or completing wells in the southern delaware basin and acquiring or extending unproved leases , partially offset by $ 1.1 million in cash proceeds from the sale of non-core properties .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```capital resources and liquidity our primary cash requirements are for capital expenditures , working capital , operating expenses , acquisitions and principal and interest payments on indebtedness . our primary sources of liquidity are cash generated by operations , net of the realized effect of our hedging agreements , and amounts available to be drawn under our credit facility . the table below summarizes certain measures of liquidity and capital expenditures , as well as our sources of capital from internal and external sources , for the periods indicated , in thousands . replace_table_token_26_th cash flow from operating activities , including changes in working capital , provided approximately $ 23.5 million in cash for the year ended december 31 , 2018 compared to $ 34.7 million for the year ended december 31 , 2017. cash flow from operating activities , excluding changes in working capital , provided approximately $ 22.1 million in cash for the year ended december 31 , 2018 compared to $ 29.6 million for the year ended december 31 , 2017. cash provided due to changes in working capital were approximately $ 1.4 million during 2018 , compared to $ 5.1 million during 2017 and represent normal receivable and payable activity during the period . net cash flows used in investing activities were $ 30.7 million for the year ended december 31 , 2018. we expended $ 59.0 million in cash capital costs , primarily related to drilling and or completing wells in the southern delaware basin and acquiring or extending unproved leases , partially offset by $ 27.8 million in cash proceeds from the sale of our non-core properties . net cash flows used in investing activities were $ 65.5 million for the year ended december 31 , 2017. we expended $ 66.6 million in cash capital costs , primarily related to drilling and or completing wells in the southern delaware basin and acquiring or extending unproved leases , partially offset by $ 1.1 million in cash proceeds from the sale of non-core properties .
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 Suspicious Activity Report : actual results could differ from those estimates . significant estimates with regard to these financial statements include estimates of remaining proved natural gas and oil reserves , the timing and costs of our future drilling , development and abandonment activities , and income taxes . see “ item 1a . risk factors ” for a more detailed discussion of a number of other factors that affect our business , financial condition and results of operations . 52 going concern assessment as discussed below under “ capital resources and liquidity , ” our credit facility ( as defined below ) currently matures on october 1 , 2019. over the past few months , we have been in discussions with our current lenders and other sources of capital regarding a possible refinancing and or replacement of our existing credit facility . there is no assurance , however , that such discussions will result in a refinancing of the credit facility on acceptable terms , if at all , or provide any specific amount of additional liquidity for future capital expenditures . these conditions raise substantial doubt about our ability to continue as a going concern . however , the accompanying financial statements have been prepared assuming we will continue to operate as a going concern , which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business . the accompanying financial statements do not include adjustments that might result from the outcome of the uncertainty , including any adjustments to reflect the possible future effects of the recoverability and classification of recorded asset amounts or amounts and classifications of liabilities that might be necessary should we be unable to continue as a going concern . as discussed below under “ capital resources and liquidity , ” management is evaluating plans to refinance and or replace the credit facility . results of operations the table below sets forth our average net daily production data in mmcfe/d from our fields for each of the periods indicated : replace_table_token_22_th ( 1 ) includes a decreased production rate of 4.2 mmcfe/d due to downtime related to compressor installation and maintenance during the three months ended june 30 , 2018. our gom production was not materially affected by hurricane michael which passed through the northeastern gom in october 2018 . ( 2 ) includes a decreased production rate of 0.8 mmcfe/d due to temporary pipeline limitations during the three months ended june 30 , 2017 and 0.5 mmcfe/d for the three months ended december 31 , 2018 . ( 3 ) south timbalier 17 ceased production in august 2017 . ( 4 ) includes woodbine production from madison and grimes counties and conventional production in others . decrease in production during three months ended december 31 , 2018 is primarily due to the liberty and hardin county property sale in november 2018 . ( 5 ) includes eagle ford and buda production from karnes , zavala and dimmit counties , and conventional production in others , prior to june 30 , 2018. does not include karnes county in the three months ended june 30 , 2018 and forward due to its sale in march 2018 . ( 6 ) includes onshore wells primarily in east texas and wyoming . 53 year ended december 31 , 2018 compared to year ended december 31 , 2017 the table below sets forth revenue , production data , average sales prices and average production costs associated with our sales of natural gas , oil and natural gas liquids ( `` ngls `` ) from continuing operations for the years ended december 31 , 2018 and 2017. oil , condensate and ngls are compared with natural gas in terms of cubic feet of natural gas equivalents . one barrel of oil , condensate or ngl is the energy equivalent of six mcf of natural gas . reported operating expenses include production taxes , such as ad valorem and severance . replace_table_token_23_th 54 replace_table_token_24_th 55 natural gas , oil and ngl sales and production all of our revenues are from the sale of our natural gas , crude oil and natural gas liquids production . our revenues may vary significantly from year to year depending on changes in commodity prices , which fluctuate widely , and production volumes . our production volumes are subject to wide swings as a result of new discoveries , weather and mechanical related problems . in addition , the production rate associated with our oil and gas properties declines over time as we produce our reserves . we reported revenues of approximately $ 77.1 million for the year ended december 31 , 2018 , compared to revenues of approximately $ 78.5 million for the year ended december 31 , 2017. this slight decrease in revenues was primarily due to a reduction in natural gas production attributable to 2018 non-core property sales , the expected year over year decline in our offshore properties and the reduction in our fourth quarter 2018 drilling program in response to declining oil prices ; declines which were substantially offset by the benefit of higher commodity prices in 2018. total production for the year ended december 31 , 2018 was approximately 16.0 bcfe , or 43.9 mmcfe/d , compared to approximately 20.1 bcfe , or 55.1 mmcfe/d , in the prior year . the decrease was attributable to an approximate 13 mmcfe/d decline in production resulting from normal field decline , an approximate 2 mmcfe/d decline due to non-core property sales , and an approximate 1 mmcfe/d decline due to shut-in periods at eugene island for compressor installation in june . partially offsetting these decreases in production was an increase of approximately 4 mmcfe/d of new production ( 88 % oil and ngls ) from drilling on our southern delaware basin acreage . story_separator_special_tag holding all other factors constant , a reduction in the company 's proved reserve estimate at december 31 , 2018 of 5 % , 10 % and 15 % would affect depreciation , depletion and amortization expense by approximately $ 0.4 million , $ 0.9 million and $ 1.4 million , respectively . impairment of natural gas and oil properties the company reviews its proved natural gas and oil properties for impairment whenever events and circumstances indicate a potential decline in the recoverability of their carrying value . an impairment loss associated with an asset group is the amount by which the carrying amount of a long-lived asset is not recoverable and exceeds its fair value . an asset 's fair value is preferably indicated by a quoted market price in the asset 's principal market . unlike many businesses where independent appraisals can be obtained for items such as equipment , oil and gas proved reserves are unique assets . most oil and gas valuations are based on a combination of the income approach and market approach methodologies . we utilize the income approach also known as the discounted cash flow ( “ dcf ” ) approach . under the dcf method in determining fair value , there are specific guidelines and ranges within the evaluation that we can consider and estimate . the company compares expected undiscounted future net cash flows from each field to the unamortized capitalized cost of the asset . if the future undiscounted net cash flows , based on the company 's estimate of future natural gas and oil prices and operating costs and anticipated production from proved reserves , are lower than the unamortized capitalized cost , then the capitalized cost is reduced to fair market value . the factors used to determine fair value include , but are not limited to , estimates of reserves , future commodity pricing , future production estimates and anticipated capital expenditures . unproved properties are reviewed quarterly to determine if there has been impairment of the carrying value , with any such impairment charged to expense in the period . drilling activities in an area by other companies may also effectively impair leasehold positions . given the complexities associated with natural gas and oil reserve estimates and the history of price volatility in the natural gas and oil markets , events may arise that will require the company to record an impairment of its natural gas and oil properties and there can be no assurance that such impairments will not be required in the future nor that they will not be material . assuming strip pricing as of march 1 , 2019 through 2023 and keeping pricing flat thereafter , instead of 2018 sec pricing , while leaving all other parameters unchanged , the company 's proved reserves would have been 84.8 bcfe and the pv-10 value of proved reserves would have been $ 145.4 million . 61 derivative instruments the company elected to not designate any of its derivative positions for hedge accounting at the end of each reporting period we record on our balance sheet the mark-to-market valuation of our derivative instruments . the estimated change in fair value of the derivatives , along with the realized gain or loss for settled derivatives , is reported in “ other income ( expense ) ” as “ gain on derivatives , net ” . income taxes income taxes are provided for the tax effects of transactions reported in the financial statements and consist of taxes currently payable plus deferred income taxes related to certain income and expenses recognized in different periods for financial and income tax reporting purposes . deferred income taxes are measured by applying currently enacted tax rates to the differences between financial statements and income tax reporting . numerous judgments and assumptions are inherent in the determination of deferred income tax assets and liabilities as well as income taxes payable in the current period . we are subject to taxation in several jurisdictions , and the calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax laws and regulations in various taxing jurisdictions . accounting for uncertainty in income taxes prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of income tax positions taken or expected to be taken in an income tax return . for those benefits to be recognized , an income tax position must be more-likely-than-not to be sustained upon examination by taxing authorities . in assessing the realizability of deferred tax assets , we consider whether it is more likely than not that some portion or all of the deferred tax assets will not be realized . as of december 31 , 2018 , we had federal net operating loss ( “ nol ” ) carryforwards of $ 380.8 million . generally , these nols are available to reduce future taxable income and the related income tax liability subject to the limitations set forth in section 382. however , these nols are subject to an annual section 382 limitation as a result of the ownership change that occurred in connection with our stock offering in november 2018. given our annual section 382 limitation and the uncertainty of our ability to generate taxable income , a valuation allowance of $ 71.0 million has been recorded for the year ended december 31 , 2018 against the deferred tax assets , reduced by the amount of the deferred tax liability . our federal and state income tax returns are generally not filed before the consolidated financial statements are prepared . therefore , we estimate the tax basis of our assets and liabilities at the end of each period as well as the effects of tax rate changes , tax credits and net operating and capital loss carryforwards and carrybacks . adjustments related to differences between the estimates we used and actual amounts we reported are recorded in the period in

