SEGMENT INFORMATION Our reportable business segments are Rig Services, Fishing and Rental Services, Coiled Tubing Services and Fluid Management Services. We also have a Functional Support segment associated with overhead and other costs in support of our reportable segments. We evaluate the performance of our segments based on gross margin measures. All inter-segment sales pricing is based on current market conditions. Rig Services Our Rig Services include the completion of newly drilled wells, workover and recompletion of existing oil and natural gas wells, well maintenance, and the plugging and abandonment of wells at the end of their useful lives. We also provide specialty drilling services to oil and natural gas producers with certain of our larger rigs that are capable of providing conventional and horizontal drilling services. Our rigs encompass various sizes and capabilities, allowing us to service all types of wells. Many of our rigs are outfitted with our proprietary KeyView technology, which captures and reports well site operating data and provides safety control systems. We believe that this technology allows our customers and our crews to better monitor well site operations, improves efficiency and safety, and adds value to the services that we offer. The completion and recompletion services provided by our rigs prepare wells for production, whether newly drilled, or recently extended through a workover operation. The completion process may involve selectively perforating the well casing to access production zones, stimulating and testing these zones, and installing tubular and downhole equipment. We typically provide a well service rig and may also provide other equipment to assist in the completion process. Completion services vary by well and our work may take a few days to several weeks to perform, depending on the nature of the completion. The workover services that we provide are designed to enhance the production of existing wells and generally are more complex and time consuming than normal maintenance services. Workover services can include deepening or extending wellbores into new formations by drilling horizontal or lateral wellbores, sealing off depleted production zones and accessing previously bypassed production zones, converting former production wells into injection wells for enhanced recovery operations and conducting major subsurface repairs due to equipment failures. Workover services may last from a few days to several weeks, depending on the complexity of the workover. Maintenance services provided with our rig fleet are generally required throughout the life cycle of an oil or natural gas well. Examples of these maintenance services include routine mechanical repairs to the pumps, tubing and other equipment, removing debris and formation material from wellbores, and pulling rods and other downhole equipment from wellbores to identify and resolve production problems. Maintenance services are generally less complicated than completion and workover related services and require less time to perform. Our rig fleet is also used in the process of permanently shutting-in oil or natural gas wells that are at the end of their productive lives. These plugging and abandonment services generally require auxiliary equipment in addition to a well servicing rig. The demand for plugging and abandonment services is not significantly impacted by the demand for oil and natural gas because well operators are required by state regulations to plug wells that are no longer productive. Fishing and Rental Services We offer a full line of fishing services and rental equipment designed for use in providing drilling and workover services. Fishing services involve recovering lost or stuck equipment in the wellbore utilizing a broad array of fishing tools. Our rental tool inventory consists of drill pipe, tubulars, handling tools (including our patented Hydra-Walk  pipe-handling units and services), pressure-control equipment, pumps, power swivels, reversing units and foam air units. We sold our well testing assets and our frac stack equipment used to support hydraulic fracturing operations and the associated flowback of frac fluids in the second quarter of 2017. Demand for our fishing and rental services is closely related to capital spending by oil and natural gas producers, which is generally a function of oil and natural gas prices. Coiled Tubing Services Coiled Tubing Services involve the use of a continuous metal pipe spooled onto a large reel which is then deployed into oil and natural gas wells to perform various applications, such as wellbore clean-outs, nitrogen jet lifts, through-tubing fishing, and formation stimulations utilizing acid and chemical treatments. Coiled tubing is also used for a number of horizontal well applications such as milling temporary isolation plugs that separate frac zones, and various other pre- and post-hydraulic fracturing well preparation services. Fluid Management Services We provide transportation and well-site storage services for various fluids utilized in connection with drilling, completions, workover and maintenance activities. We also provide disposal services for fluids produced subsequent to well completion. These fluids are removed from the well site and transported for disposal in saltwater disposal wells owned by us or a third party. In addition, we operate a fleet of hot oilers capable of pumping heated fluids used to clear soluble restrictions in a wellbore. Demand and pricing for these services generally correspond to demand for our well service rigs. Functional Support Our Functional Support segment includes unallocated overhead costs associated with administrative support for our reporting segments. Financial Summary The following tables set forth our unaudited segment information as of and for the three months ended March 31, 2019 and 2018 (in thousands): As of and for the three months ended March 31, 2019 Rig Services Fishing and Rental Services Coiled Tubing Services Fluid Management Services Functional Support Reconciling Eliminations Total Revenues from external customers $ 65,026 $ 14,587 $ 10,673 $ 18,987 $  $  $ 109,273 Intersegment revenues 88 908  43  (1,039 )  Depreciation and amortization 5,989 4,150 1,256 2,441 460  14,296 Other operating expenses 54,581 11,560 11,555 16,437 16,156  110,289 Operating income (loss) 4,456 (1,123 ) (2,138 ) 109 (16,616 )  (15,312 ) Interest expense, net of amounts capitalized 10 7 16 11 9,189  9,233 Income (loss) before income taxes 4,469 (1,124 ) (2,153 ) 106 (24,701 )  (23,403 ) Long-lived assets(1) 134,880 49,352 17,368 53,168 19,023  273,791 Total assets 185,482 61,353 27,417 66,407 62,841 9,252 412,752 Capital expenditures 1,830 2,073 766 157 214  5,040 As of and for the three months ended March 31, 2018 Rig Services Fishing and Rental Services Coiled Tubing Services Fluid Management Services Functional Support Reconciling Eliminations Total Revenues from external customers $ 70,304 $ 13,835 $ 18,423 $ 22,754 $  $  $ 125,316 Intersegment revenues 65 515 9 351  (940 )  Depreciation and amortization 7,787 5,754 1,172 5,179 464  20,356 Other operating expenses 59,567 12,033 13,319 20,639 17,227  122,785 Operating income (loss) 2,950 (3,952 ) 3,932 (3,064 ) (17,691 )  (17,825 ) Interest expense, net of amounts capitalized     8,144  8,144 Income (loss) before income taxes 3,006 (3,945 ) 3,932 (3,028 ) (24,927 )  (24,962 ) Long-lived assets(1) 155,688 57,971 20,419 70,275 130,559 (105,733 ) 329,179 Total assets 212,529 69,762 38,943 86,595 189,836 (95,666 ) 501,999 Capital expenditures 3,466 366 3,057 1,483 1,072  9,444 (1) Long-lived assets include fixed assets, intangibles and other non-current assets.