IN THE SUPREME COURT OF TEXAS

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No. 19-0545 

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REGENCY FIELD SERVICES, LLC, ET AL., PETITIONERS, 

v. 

SWIFT ENERGY OPERATING, LLC, RESPONDENT

══════════════════════════════════════════ 

ON PETITION FOR REVIEW FROM THE

COURT OF APPEALS FOR THE FOURTH DISTRICT OF TEXAS

══════════════════════════════════════════ 

Argued December 3, 2020 

JUSTICE BOYD delivered the opinion of the Court. 

JUSTICE GUZMAN did not participate in the decision. 

Upon the wicked he shall rain snares, fire and brimstone, and an 

horrible tempest: this shall be the portion of their cup.1 

Brimstone—more commonly (but perhaps less captivatingly) known as sulfur2—has long 

been associated with death, destruction, and devastation. Yet the element, used in chemical 

weapons as early as ancient Greece,3 exists naturally with the gas and petroleum that lay in 

abundance below the surface of our state. As natural gas is drawn to the surface, sulfur—in the 

form of hydrogen sulfide—often arrives with it. In this case, a mineral estate lessee alleges that 

1 Psalms 11:6 (King James). 

2 See, e.g., Psalms 11:6 (New International). 

3 See 2 EDWARD GIBBON, THE HISTORY OF THE DECLINE AND FALL OF THE ROMAN EMPIRE 291–92 (John 

Bagnell Bury ed., Liberty Fund, Inc. 2011) (1906). 
2 

hydrogen sulfide an operator injected back into the earth has migrated beneath the surface and 

injured the lessee’s interests in the minerals underlying nearby properties. 

This appeal concerns the specific issue of when, for purposes of the statute of limitations, 

the lessee’s claims accrued. More specifically, the issue is whether the pleadings and summaryjudgment evidence conclusively established that the lessee’s claims accrued at least two years 

before the lessee first filed them. The trial court held they did. The court of appeals reversed in 

part, holding that limitations bars the lessee’s claims for injuries to its interests in one of its nine 

separate leases, but does not bar the lessee’s claims for injuries to its interests in the other eight 

leases. 

We conclude that the pleadings and evidence did not conclusively establish whether or 

when the lessee sustained any legal injury as a result of the defendant’s alleged wrongful conduct. 

Because of this conclusion, and in light of the lessee’s arguments in this Court, we need not decide 

whether the lessee’s claims accrued separately on a lease-by-lease basis. Even assuming they all 

accrued when the defendant’s alleged wrongful conduct first caused the lessee to suffer a legal 

injury, the pleadings and evidence do not conclusively establish that the first legal injury occurred 

more than two years before the lessee filed its claims. We thus reverse the court of appeals’ 

judgment in part and remand the case to the trial court for further proceedings. 

I. 

Background 

Natural gas is either “sweet” or “sour.” Sour gas, which contains high levels of hydrogen 

sulfide, is “unfit for use in generating light or fuel for domestic purposes.” TEX. NAT. RES. CODE
3 

§ 86.002(8).4 Often described as smelling like rotten eggs, hydrogen sulfide is extremely 

“poisonous, corrosive, flammable, and explosive.” French v. Occidental Permian Ltd., 440 

S.W.3d 1, 6 n.14 (Tex. 2014). Among other things, it contaminates hydrocarbons and destroys 

wells and equipment used to produce them. 

Natural gas producers can treat sour gas to remove the hydrogen sulfide. But then they 

must carefully dispose of it. Sometimes they burn (or “flare”) it off or haul it away to a disposal 

site. But they may also dispose of it by injecting it through a well into a depleted subsurface 

reservoir. See 16 TEX. ADMIN. CODE § 3.9(1); R.R. Comm’n of Tex. v. Tex. Citizens for a Safe 

Future & Clean Water, 336 S.W.3d 619, 621 (Tex. 2011). Those who plan to operate such an 

injection well must first obtain a permit from the Texas Railroad Commission. See TEX. WATER 

CODE § 27.031. To obtain a permit, the operator must give notice of its application to all 

“interested” and “affected” persons, including the “operator of any well located within one-half 

mile of the proposed disposal well” and the “owners of record of each surface tract that adjoins 

the proposed disposal tract.” See 16 TEX. ADMIN. CODE § 3.9(5). 

Regency Field Services owns and operates a disposal injection well in McMullen County, 

known as the Tilden Acid Gas Injection Well. The permit Regency first received in 2007 allowed 

it to inject a particular amount of a hydrogen-sulfide/carbon-dioxide mix (called “injectate”) into 

the Wilcox geological formation, a long-depleted gas field that runs horizontally around 5,800 feet 

beneath the surface. Above the Wilcox formation, around 5,000 feet beneath the surface, lies the 

Carrizo aquifer, one of the state’s largest water sources. Below the Wilcox lie the Olmos formation 

4 See also TEX. NAT. RES. CODE § 86.002(9) (defining “sweet gas” as “all gas except sour gas and casinghead 

gas”); Bowden v. Phillips Petroleum Co., 247 S.W.3d 690, 703 n.6 (Tex. 2008) (comparing sweet and sour gas). 
4 

(around 9,400 feet deep) and the Eagle Ford formation (around 11,000 feet deep), two of the state’s 

highest-producing natural-gas fields. Impermeable layers of shale separate the Wilcox from the 

formations above and below it, but injectate placed into the Wilcox will spread horizontally away 

from the injection point over time. The Railroad Commission granted Regency a permit to operate 

the Tilden injection well based on models predicting that the injectate “plume” would take forty 

years to migrate 2,220 feet. 

In 2011, Regency applied for an amended permit allowing it to increase the amount of 

injectate it placed into the Tilden injection well. Regency’s application included new models 

predicting that, at the increased disposal rate, the plume would take thirty years to migrate 2,900 

feet from the injection point. The Commission granted the application and issued the amended 

permit in February 2012. 

About six months later, Layline Petroleum discovered hydrogen sulfide in one of its wells 

located 3,300 feet from Regency’s injection well. Layline’s well—the JCB Horton #1—was 

located on the Quintanilla Ranch, a 4,200-acre tract adjacent to the land on which the injection 

well is located. The Horton #1 well produced gas from the Olmos formation, so its wellbore 

necessarily traveled through the Wilcox formation. Studies confirmed that the hydrogen sulfide 

discovered in the Horton #1 well came from Regency’s injection well. As a result of the 

contamination, Layline had to cap and plug the Horton #1 well and perform other remedial 

measures. Regency temporarily shut in the injection well while it performed its own remedial 

measures. The Railroad Commission then authorized Regency to resume operating the injection 

well, but at reduced injection rates and pressure. 
5 

Swift Energy Operating holds nine mineral leases covering different depths underlying 

separate tracts near Regency’s injection well. One lease—the PCQ lease—covers all of the 

Quintanilla Ranch except for certain areas previously leased to others, including the area on which 

the Horton #1 well was located. The PCQ lease gives Swift the right to explore and produce all of 

the minerals under and around the Horton #1 well, which already existed when Swift obtained the 

PCQ lease in 2009. So to reach the Horton #1 well, the hydrogen sulfide injectate necessarily had 

to physically migrate through some area under the Quintanilla Ranch where Swift holds the 

mineral lease. Swift’s other eight leases cover various depths under separate tracts located north 

and east of Regency’s injection well. On October 23, 2012, Layline notified Swift that Layline had 

to plug the Horton #1 well because of the hydrogen sulfide contamination. A revised modeling 

study that Regency obtained in 2013 showed that the hydrogen sulfide may have crossed under 

the surface boundary of the Quintanilla Ranch as early as April 2009. 

In July 2014, the Quintanilla family and others filed this suit against Regency. Other nearby 

property owners intervened as plaintiffs that same month. Swift intervened on September 24, 2015, 

more than three years after Layline first discovered hydrogen sulfide at the Horton #1 well. After 

settling with the Quintanillas and the other claimants, Regency moved for summary judgment on 

Swift’s claims based on limitations. The trial court granted Regency’s motion and dismissed 

Swift’s claims. Swift appealed, and the court of appeals affirmed in part and reversed in part. Swift 

Energy Operating, LLC v. Regency Field Servs. LLC, 608 S.W.3d 214 (Tex. App.—San Antonio 

2019). 

The court of appeals held that Regency was entitled to summary judgment to the extent 

Swift’s claims are based on its interests under the PCQ lease because the evidence established that 
6 

“the injectate plume had crossed the PCQ lease’s western border and into Swift’s PCQ lease” no 

later than October 2012. Id. at 220. But because the evidence did not establish whether or when 

the injectate “breache[d] the boundary” of the tracts covered by the other eight leases or when it 

first “substantially interfere[d]” with Swift’s rights under those leases, the court reversed the 

summary judgment to the extent Swift’s claims are based on injuries to its interests under the other 

leases. Id. at 221–22. Both Regency and Swift filed petitions for review in this Court, which we 

granted. Together, the petitions present the issue of whether, for purposes of its summary-judgment 

motion, Regency conclusively established that Swift’s claims asserting injuries to its interests 

under the PCQ lease or under its other leases accrued more than two years before Swift first filed 

its claims. 

II. 

Accrual Rules 

We begin by reviewing the rules that govern accrual of a legal claim for purposes of 

applying a statute of limitations. Statutes of limitations 

afford plaintiffs what the legislature deems a reasonable time to 

present their claims and protect defendants and the courts from 

having to deal with cases in which the search for truth may be 

seriously impaired by the loss of evidence, whether by death or 

disappearance of witnesses, fading memories, disappearance of 

documents or otherwise. 

Murray v. San Jacinto Agency, Inc., 800 S.W.2d 826, 828 (Tex. 1990). The parties here agree that 

the applicable limitations statute required Swift to file suit against Regency within two years after 

its claims accrued.5 As we explain, the legal-injury rule determines when an injured party’s claims 

5 See TEX. CIV. PRAC. & REM.CODE § 16.003(a) (requiring suit for trespass, conversion, or taking of property 

be brought “not later than two years after the day the cause of action accrues”). 
7 

accrue, and the single-action rule requires the party to bring all claims arising from the defendant’s 

wrongful conduct in a single legal action. Although we have recognized exceptions to these general 

rules, Swift does not rely on any exceptions for purposes of this appeal. 

A. The legal-injury rule 

Generally, a claim accrues when the defendant’s wrongful conduct causes the claimant to 

suffer a legal injury,6 which gives the claimant the right to seek a judicial remedy.7 Am. Star Energy 

& Mins. Corp. v. Stowers, 457 S.W.3d 427, 430 (Tex. 2015).8 Once the defendant’s wrongful 

conduct causes a legal injury, the injured party’s claims based on that wrongful conduct accrue—

and the limitations period begins to run—even if (1) the claimant does not yet know that a legal 

injury has occurred,9 (2) the claimant has not yet experienced, or does not yet know the full extent 

of, the legal injury,10 (3) the claimant does not yet know the specific cause of the injury or the party 

6 Schlumberger Tech. Corp. v. Pasko, 544 S.W.3d 830, 834 (Tex. 2018) (per curiam); Sw. Energy Prod. Co. 

v. Berry–Helfand, 491 S.W.3d 699, 721 (Tex. 2016); Childs v. Haussecker, 974 S.W.2d 31, 36 (Tex. 1998); S.V. v. 

R.V., 933 S.W.2d 1, 4 (Tex. 1996); Moreno v. Sterling Drug, Inc., 787 S.W.2d 348, 351 (Tex. 1990); Stillwell v. City 

of Fort Worth, 169 S.W.2d 486, 487 (Tex. 1943). 

7 Exxon Mobil Corp. v. Rincones, 520 S.W.3d 572, 591 (Tex. 2017); ExxonMobil Corp. v. Lazy R Ranch, LP, 

511 S.W.3d 538, 542 (Tex. 2017); Exxon Corp. v. Emerald Oil & Gas Co., L.C., 348 S.W.3d 194, 202 (Tex. 2011); 

Schneider Nat’l Carriers, Inc. v. Bates, 147 S.W.3d 264, 279 (Tex. 2004); Murray, 800 S.W.2d at 828; City of Abilene 

v. Downs, 367 S.W.2d 153, 160 (Tex. 1963). 

8 See Archer v. Tregellas, 566 S.W.3d 281, 289–90 (Tex. 2018); Provident Life & Accident Ins. Co. v. Knott, 

128 S.W.3d 211, 221 (Tex. 2003); see also Hous. Water-Works Co. v. Kennedy, 8 S.W. 36, 37 (Tex. 1888) (explaining 

claim accrues upon suffering a legal injury “by which is meant an injury giving cause of action by reason of its being 

an invasion of a plaintiff’s right”).

9 Schlumberger, 544 S.W.3d at 834; Town of Dish v. Atmos Energy Corp., 519 S.W.3d 605, 609, 612 (Tex. 

2017); Sw. Energy Prod., 491 S.W.3d at 721; Provident Life, 128 S.W.3d at 221; Childs, 974 S.W.2d at 36; S.V., 933 

S.W.2d at 4; Moreno, 787 S.W.2d at 351. 

10 Lazy R Ranch, 511 S.W.3d at 542–43; Velsicol Chem. Corp. v. Winograd, 956 S.W.2d 529, 531 (Tex. 

1997). 
8 

responsible for it,11 (4) the wrongful conduct later causes additional legal injuries,12 or (5) the 

claimant has not yet sustained or cannot yet ascertain any or all of the damages resulting from the 

legal injuries.13 

B. The single-action rule 

Closely related to the legal-injury rule, the “single-action rule” recognizes that a 

defendant’s wrongful conduct may breach multiple legal duties, produce multiple legal injuries, or 

cause multiple types of damages, and thus give rise to multiple causes of action. See Jaster v. 

Comet II Constr., Inc., 438 S.W.3d 556, 563–65 (Tex. 2014) (plurality op.) (explaining distinction 

between common meanings of “action,” which “refers to an entire lawsuit or cause or proceeding,” 

and “claims” or “causes of action” asserted within an action).14 Because each claim or cause of 

action may allege different legal injuries, they could—at least in theory—each accrue at different 

times, even though they arise from the same wrongful conduct. But under the single-action rule, a 

defendant’s wrongful conduct gives rise to a single, indivisible action in which the claimant must 

pursue all claims for all damages resulting from all injuries that arise from the wrongful conduct, 

11 PPG Indus., Inc. v. JMB/Hous. Ctrs. Partners Ltd. P’ship, 146 S.W.3d 79, 93–94 (Tex. 2004). 

12 Schlumberger, 544 S.W.3d at 834 (“[I]njuries that arise or develop after the legal injury are still deemed 

to have accrued on the same date as the legal injury that caused them.”); Atlas Chem. Indus., Inc. v. Anderson, 524 

S.W.2d 681, 684 (Tex. 1975). 

13 Schlumberger, 544 S.W.3d at 834; Rincones, 520 S.W.3d at 591; Sw. Energy Prod., 491 S.W.3d at 721; 

Provident Life, 128 S.W.3d at 221; Childs, 974 S.W.2d at 36; S.V., 933 S.W.2d at 4; Murray, 800 S.W.2d at 828; 

Tenn. Gas Transmission Co. v. Fromme, 269 S.W.2d 336, 338 (Tex. 1954); Quinn v. Press, 140 S.W.2d 438, 440 

(Tex. 1940); cf. Crosstex N. Tex. Pipeline, L.P. v. Gardiner, 505 S.W.3d 580, 594 (Tex. 2016) (explaining distinction 

between a legal injury, the wrongful act (or “breach of a duty”) that “gives rise to liability for the legal injury,” and 

“the damages that may be awarded as compensation for the legal injury”). 

14 See, e.g., Innovative Block of S. Tex., Ltd. v. Valley Builders Supply, Inc., 603 S.W.3d 409, 417–18 (Tex. 

2020) (recognizing that the same wrongful conduct may support both defamation and business-disparagement causes 

of action but distinguishing between the two based on the type of damages alleged). 
9 

and those claims all accrue when the first such injury occurs. Pustejovsky v. Rapid-Am. Corp., 35 

S.W.3d 643, 646 (Tex. 2000). 

In this case, for example, Swift asserted “causes of action” for trespass, negligence, gross 

negligence, and “nuisance,”15 all allegedly caused by Regency’s wrongful operation of the Tilden 

injection well. Generally, a negligence claim accrues when the defendant’s negligent conduct 

causes any legal injury for which the claimant may obtain legal relief.16 When the claimant alleges 

that the defendant wrongfully caused a nuisance, the claim accrues when the defendant’s conduct 

15 In its original plea in intervention, Swift asserted only causes of action for trespass and negligence. It added 

causes of action for gross negligence and “nuisance” to its second amended plea, which it filed a few months before 

we clarified that “the term ‘nuisance’ refers not to a defendant’s conduct or to a legal claim or cause of action but to 

a type of legal injury involving interference with the use and enjoyment of real property.” Crosstex, 505 S.W.3d at 

588. Although Swift continued to plead “nuisance” as a “cause of action” in its third amended plea, filed about two 

months after we decided Crosstex, it identified the “nuisance” as a particular injury, as it has continued to identify it 

in its briefs. Swift pleaded that the nuisance resulted from Regency’s “conduct that was negligent, reckless, grossly 

negligent, intentional and unreasonable.” We explained in Crosstex that “a defendant can be liable for causing a 

nuisance if the defendant intentionally causes it, negligently causes it, or—in limited circumstances—causes it by 

engaging in abnormally dangerous or ultra-hazardous activities.” Id.

16 Under the general legal-injury rule, for example, a claim that an attorney negligently gave faulty legal 

advice accrues when the “advice is taken” because that’s when “injury is incurred.” Erikson v. Renda, 590 S.W.3d 

557, 563 (Tex. 2019). A claim that an insurance agent negligently failed to obtain coverage accrues when coverage is 

denied because that’s when the claimant “sustain[s] injury.” Johnson & Higgins of Tex., Inc. v. Kenneco Energy, Inc., 

962 S.W.2d 507, 514 (Tex. 1998). A claim that a tax accountant negligently gave faulty advice accrues when the 

“advice is taken” because that’s when the client “suffers legal injury.” Murphy v. Campbell, 964 S.W.2d 265, 270 

(Tex. 1997); see also Atkins v. Crosland, 417 S.W.2d 150, 153 (Tex. 1967) (holding negligence claim against tax 

accountant “did not arise until the tax deficiency was assessed by the Commissioner of Internal Revenue” because 

“[p]rior to assessment the plaintiff had not been injured”). A claim for negligent design or construction accrues “as 

soon as the owner suffers some injury.” Trinity River Auth. v. URS Consultants, Inc.-Tex., 889 S.W.2d 259, 262 (Tex. 

1994). Early on, we explained that a negligence claim accrues at the time of the defendant’s wrongful act when the 

act was not “itself lawful” and was itself “a legal injury . . . giving cause of action by reason of its being an invasion 

of a plaintiff’s right.” Hous. Water-Works, 8 S.W. at 37; see also Quinn, 140 S.W.2d at 441 (“A cause of action based 

upon negligence . . . accrues at the time of the wrongful act, and consequently limitation commences to run at that 

time and not at the time of the ascertainment of damages, if any.”). As we later explained, this is true when, or 

“because,” an unlawful, wrongful act itself causes or constitutes “a legal injury.” Trinity River Auth., 889 S.W.2d at 

262; see Lonny Hoffman & Bret Wells, The Exceptions Prove the Rule: Recalibrating the Discovery Rule and 

Equitable Fraud Exceptions to the Legal Injury Rule, 71 BAYLOR L. REV. 63, 76 (2019) (“If the attempted distinction 

that Houston Water-Works tried to draw between originally lawful and unlawful acts feels convoluted and 

unworkable, it certainly was. But the court kept citing the case—and still does, to this day, though it has largely paid 

only lip service to the antiquated distinction. Instead, the case has come to be understood more basically as articulating 

the modern conception of the legal injury rule—that a cause of action accrues when a wrongful act causes some legal 

injury.”). 
10 

“first ‘substantially interferes with the use and enjoyment of land by causing unreasonable 

discomfort or annoyance to persons of ordinary sensibilities,’” because that’s when the nuisance 

(the legal injury) first occurs. Town of Dish, 519 S.W.3d at 609 (quoting Nat. Gas Pipeline Co. of 

Am. v. Justiss, 397 S.W.3d 150, 153 (Tex. 2012) (in turn quoting Schneider, 147 S.W.3d at 269–

70)).17 And a claim for trespass to non-possessory property rights under a mineral lease (as Swift 

asserts here) arises when the defendant’s unauthorized conduct first invades or interferes with the 

claimant’s legal rights “to explore, obtain, produce, and possess the minerals subject to the lease,” 

because that invasion or interference constitutes the actionable legal injury.18 Lightning Oil, 520 

S.W.3d at 49.19

17 See also Crosstex, 505 S.W.3d at 600 (confirming definition of “nuisance” as a legal injury). 

18 By contrast, a trespass claim alleging unauthorized physical entry upon the claimant’s land or other 

invasion of a possessory property interest generally accrues when the unauthorized entry occurs, even if the entry does 

not cause a discernable injury or damages. Lightning Oil Co. v. Anadarko E&P Onshore, LLC, 520 S.W.3d 39, 49 

(Tex. 2017); see also Coastal Oil & Gas Corp. v. Garza Energy Tr., 268 S.W.3d 1, 11 n.28 (Tex. 2008). This is 

because the violation of the claimant’s exclusive possessory right itself constitutes an “injury to the right of 

possession” for which the claimant is authorized to seek a judicial remedy. Coastal Oil, 268 S.W.3d at 9 (quoting 

Pentagon Enters. v. Sw. Bell Tel. Co., 540 S.W.2d 477, 478 (Tex. App.—Houston [14th Dist.] 1976, writ ref’d n.r.e.)); 

see also id. at 12 n.36 (quoting McDaniel Bros. v. Wilson, 70 S.W.2d 618, 621 (Tex. App.—Beaumont 1934, writ 

ref’d)) (referring to claimant as the “injured party” even “if no damage is done or the injury is slight”). We have not 

decided whether subsurface migration can cause an actionable trespass to a surface owner’s possessory interest in the 

subsurface space. See Env’t Processing Sys., L.C. v. FPL Farming Ltd., 457 S.W.3d 414, 416 (Tex. 2015) (declining 

to decide “whether deep subsurface wastewater migration is actionable as a common law trespass in Texas”); FPL 

Farming Ltd. v. Env’t Processing Sys., L.C., 351 S.W.3d 306, 314–15 (Tex. 2011) (declining to decide “whether 

subsurface wastewater migration can constitute a trespass, or whether it did so in this case”); Coastal Oil, 268 S.W.3d 

at 12–13 (same). We need not decide that issue here either, because Swift asserts claims for trespass to its 

nonpossessory rights as a mineral lessee (which we did recognize in Lightning Oil), not to possessory rights as a 

landowner. 

19 We also held in Lightning Oil that “the loss of minerals [a lessee] will suffer by a well being drilled through 

its mineral estate is not a sufficient injury to support a claim for trespass” to the lessee’s non-possessory property rights 

to the minerals subject to the lease. 520 S.W.3d at 51 (emphasis added). Relying on this language, Swift urges us to 

hold that subsurface migration of contaminants does not cause a legal injury to a mineral lessee until the contaminants 

“substantially” invade or interfere with the lessee’s ability to exercise its rights under the mineral lease. We said in 

Lightning Oil, however, that a trespass occurs when the interference “infringes on the mineral lessee’s ability to 

exercise [these] rights.” Id. at 49. Because our holding in this case depends on when—rather than the extent to which—

the injectate invaded, interfered with, or infringed on Swift’s rights under its mineral leases, we need not further 

explore here when an invasion or interference could be too “insufficient” or “insubstantial” to constitute a legal injury. 
11 

Theoretically, at least, Swift could sustain each of these legal injuries to its interests in each 

of its nine leases at different times. For example, the migrating injectate could interfere with 

Swift’s rights to explore and produce minerals under one of its leases before it interferes with those 

same rights under a different lease. We have not previously applied the single-action rule to claims 

involving separate injuries to separately titled real-property interests. But assuming the singleaction rule applies to such claims, then—at least as our precedent has described it—the rule 

required Swift to bring all of its claims against Regency in one action, and limitations accrued as 

to all of the claims arising from legal injuries to all of the leases when the first of those legal 

injuries occurred. See Schneider, 147 S.W.3d at 278; Pustejovsky, 35 S.W.3d at 646; Atlas Chem., 

524 S.W.2d at 684. 

C. Exceptions to the rules 

We have recognized a handful of exceptions to these general accrual rules. For example, 

when the discovery rule applies, the claims accrue not when the wrongful conduct first causes a 

legal injury, but when the claimant first “knew or in the exercise of reasonable diligence should 

have known of the wrongful act and resulting injury.” S.V., 933 S.W.2d at 4. Similarly, “when a 

defendant has fraudulently concealed the facts forming the basis of the plaintiff’s claim, limitations 

does not begin to run until the claimant, using reasonable diligence, discovered or should have 

discovered the injury.” KPMG Peat Marwick v. Harrison Cnty. Hous. Fin. Corp., 988 S.W.2d 746, 

750 (Tex. 1999). In addition, claims asserting that a defendant’s wrongful conduct caused 

temporary (as opposed to permanent) injuries to real property may accrue separately upon “each 

subsequent” (as opposed to “the first”) resulting injury. Gilbert Wheeler, Inc. v. Enbridge Pipelines 
12 

(E. Tex.), L.P., 449 S.W.3d 474, 478 (Tex. 2014).20 And in other very limited circumstances, 

claims asserting distinct legal injuries may accrue at different times even though the same wrongful 

conduct caused the distinct injuries. Pustejovsky, 35 S.W.3d at 653 (recognizing this exception to 

the single-action rule only for “asbestos-related diseases resulting from workplace exposure”). 

Swift relied on exceptions in the trial court, arguing in response to Regency’s summaryjudgment motion that limitations does not bar its claims because Regency’s wrongful conduct 

constitutes a “continuing tort” that caused only temporary injuries. See Rincones, 520 S.W.3d at 

592 (describing the continuing-tort doctrine, which this Court has “neither endorsed nor 

addressed”) (quoting Coinmach Corp. v. Aspenwood Apartment Corp., 417 S.W.3d 909, 924 (Tex. 

2013)). But Swift expressly abandoned these arguments in the court of appeals and in this Court, 

at least for purposes of this appeal. Thus, we do not address or decide when Swift first knew or 

should have known that Regency’s wrongful conduct caused a legal injury, whether Regency 

fraudulently concealed any relevant facts, whether Swift’s alleged legal injuries could be classified 

as temporary (as opposed to permanent), whether to recognize the continuing-tort doctrine, or 

whether to establish another exception to the single-action rule. 

In particular, we need not and do not decide whether Swift’s claims alleging separate 

injuries to its separate interests under separate leases covering minerals underlying separate tracts 

accrued separately at different times. As we explain below, the pleadings and evidence do not 

conclusively establish whether or when Swift first sustained any legal injury, so limitations does 

not apply even if the single-action rule does. As a result, and in light of Swift’s arguments in this 

20 See also Schneider, 147 S.W.3d at 270 (“A permanent nuisance claim accrues when injury first occurs or is 

discovered; a temporary nuisance claim accrues anew upon each injury.”). 
13 

Court, we need not and do not address whether the single-action rule required Swift to bring all of 

its claims involving all of its separate leases in the same action, and we do not decide that any 

exception to the legal-injury rule or to the single-action rule would or would not apply under these 

or similar facts. 

III. 

Summary Judgment and the Parties’ Pleadings 

Our analysis in this case is also constrained by the fact that we are reviewing a summary 

judgment, rather than a judgment after trial on the merits. Because a statute of limitations provides 

an affirmative defense, a defendant seeking summary judgment based on limitations must 

conclusively establish that the limitations period expired before the claimant filed suit. 

Schlumberger, 544 S.W.3d at 833–34.21 To do this, the defendant must conclusively establish 

when the claimant’s action accrued. Id.22 A trial court may grant summary judgment based on 

limitations only if the defendant properly presents “deposition transcripts, interrogatory answers, 

. . . other discovery responses . . . pleadings, admissions, affidavits, stipulations of the parties, [or] 

authenticated or certified public records” showing “there is no genuine issue as to any material 

fact and the [defendant] is entitled to judgment as a matter of law” on the limitations defense. TEX.

R. CIV. P. 166a(c). 

Despite rule 166a’s reference to “pleadings,” the parties here dispute whether Regency 

could rely on the allegations contained in Swift’s pleadings to support its summary-judgment 

21 See also Justiss, 397 S.W.3d at 153; Knott, 128 S.W.3d at 219–20; Shah v. Moss, 67 S.W.3d 836, 842 

(Tex. 2001); KPMG, 988 S.W.2d at 748; Velsicol, 956 S.W.2d at 530; City of Houston v. Clear Creek Basin Auth., 

589 S.W.2d 671, 678 (Tex. 1979); Zale Corp. v. Rosenbaum, 520 S.W.2d 889, 891 (Tex. 1975) (per curiam); Downs, 

367 S.W.2d at 160. 

22 See also KPMG, 988 S.W.2d at 748; Downs, 367 S.W.2d at 160. 
14 

motion. Regency argues that, in light of Swift’s pleaded allegations, at least one of the legal injuries 

Swift alleges it sustained as a result of Regency’s alleged wrongful conduct necessarily occurred 

more than two years before Swift filed its claims. Swift argues, however, that Regency cannot rely 

on Swift’s pleaded allegations but instead must present evidence conclusively establishing when 

Regency’s wrongful conduct caused Swift to sustain a legal injury. On this point, we agree with 

Regency. 

As Swift correctly observes, pleadings generally do not qualify as summary-judgment 

“evidence,” even when they are sworn or verified. Laidlaw Waste Sys. (Dall.), Inc. v. City of 

Wilmer, 904 S.W.2d 656, 660–61 (Tex. 1995).23 Clearly, a party cannot rely on its own pleaded 

allegations as evidence of facts to support its summary-judgment motion24 or to oppose its 

opponent’s summary-judgment motion.25 But even in the summary-judgment context, pleadings 

“outline the issues,” and courts may grant summary judgment based on deficiencies in an opposing 

party’s pleadings. Hidalgo, 462 S.W.2d at 543.26

Here, Regency denies Swift’s allegations that Regency engaged in wrongful conduct or 

that its conduct caused Swift to sustain legal injuries. But Regency sought summary judgment on 

an affirmative defense, arguing that—even assuming Swift’s allegations were true—Swift 

23 See also KPMG, 988 S.W.2d at 749–50; Clear Creek Basin, 589 S.W.2d at 678; Hidalgo v. Sur. Sav. & 

Loan Ass’n, 462 S.W.2d 540, 543–44 (Tex. 1971). 

24 See Hidalgo, 462 S.W.2d at 543–44 (holding defendant’s sworn pleadings did not constitute evidence 

supporting its summary-judgment motion). 

25 See KPMG, 988 S.W.2d at 750 (holding claimant’s pleadings alleging fraudulent concealment did not 

constitute summary-judgment evidence to support that defense to limitations); Laidlaw, 904 S.W.2d at 661 (holding 

claimant’s pleadings did not create a fact issue to preclude summary judgment). 

26 See also Hidalgo, 462 S.W.2d at 543 n.1 (noting that summary judgment may “be rendered, when 

authorized, [o]n the pleadings”). 
15 

sustained one or more of its alleged legal injuries more than two years before Swift filed suit. See 

Gorman v. Life Ins. Co. of N. Am., 811 S.W.2d 542, 546 (Tex. 1991) (“[A]n affirmative defense is 

one of avoidance, rather than a defense in denial.”). To prevail on its limitations defense, Regency 

did not have to establish its own liability by proving that it in fact engaged in wrongful conduct, 

that its conduct in fact caused Swift to sustain a legal injury, or when those events occurred. See 

Justiss, 397 S.W.3d at 153 (“To establish a limitations defense, the defendant must prove that a 

[legal injury] occurred, if at all, more than two years before the [claimant’s] lawsuit.”) (emphasis 

added).27 Instead, for summary-judgment purposes, Regency could treat Swift’s pleaded 

allegations as truthful judicial admissions28 and rely on them to define the issues and determine 

whether Swift’s claims necessarily accrued beyond the limitations period. See, e.g., S.V., 933 

S.W.2d at 11 (relying on claimant’s pleadings to define the issues because she “specifically limited 

the period for which she is claiming damages”). So to determine whether Regency met its burden 

to conclusively establish that Swift sustained an alleged legal injury as a result of Regency’s 

27 See also Town of Dish, 519 S.W.3d at 611 (considering pleadings and evidence to conclude that “[a]ny 

legal injury that occurred did so at least on completion of all the compressor stations in May 2008”) (emphasis added); 

Emerald Oil, 348 S.W.3d at 205 (assuming the truth of plaintiffs’ allegations that defendant’s wrongful conduct caused 

a legal injury, “which we must for limitations analysis”), 206 (considering plaintiffs’ pleadings and evidence to 

determine when plaintiffs “had actual knowledge of this alleged injury-causing conduct”) (emphasis added); Shah, 67 

S.W.3d at 845 (assuming truth of plaintiff’s alleged standard of care and breach, which “dictate[] when limitations 

began to run”); HECI Expl. Co. v. Neel, 982 S.W.2d 881, 885 (Tex. 1998) (deciding limitations issue without deciding 

whether plaintiffs’ claims were valid under Texas law); Little v. Smith, 943 S.W.2d 414, 420 (Tex. 1997) (assuming 

the truth of the alleged wrongful conduct “for purposes of deciding the applicability of limitations); cf. Hersh v. Tatum, 

526 S.W.3d 462, 467 (Tex. 2017) (“[I]t would be impossible to determine the basis of a legal action . . . 

without considering the plaintiff’s petition.”). 

28 See Holy Cross Church of God in Christ v. Wolf, 44 S.W.3d 562, 568 (Tex. 2001) (holding party’s 

pleadings constituted a judicial admission that established when claim accrued). 
16 

alleged wrongful conduct at least two years before Swift filed its claims, we must consider both 

“the summary judgment evidence and the pleadings.” Schlumberger, 544 S.W.3d at 834.29

IV. 

Accrual of Swift’s Claims 

Swift first asserted its claims against Regency by intervening in this action on September 

24, 2015. We must decide whether Swift’s pleaded allegations and the summary-judgment 

evidence conclusively established that Swift first suffered a legal injury as a result of Regency’s 

alleged wrongful conduct on or before30 September 24, 2013. We conclude that they did not. 

A. Lease-by-lease accrual 

We first address the court of appeals’ holding that the statute of limitations bars Swift’s 

claims to the extent they allege injuries to Swift’s interests under the PCQ lease but not to the 

extent they allege injuries to Swift’s interests under its other eight nearby leases. Swift Energy 

Operating, 608 S.W.3d at 220–22. As explained, the court of appeals drew this distinction because, 

in its view, the evidence established that “the injectate plume had crossed the PCQ lease’s western 

border and into Swift’s PCQ lease” by October 2012, but did not establish whether or when the 

injectate “breache[d] the boundary” of the tracts covered by the other leases or when it first 

29 See also Fromme, 269 S.W.2d at 337 (determining limitations “from the standpoint of pleadings and 

proof”), 338 (finding accrual date based on a “careful reading of respondent’s pleadings and the evidence introduced 

in the case”). 

30 See Town of Dish, 519 S.W.3d at 608 (stating defendant bore burden to prove that claims accrued “earlier 

than” two years before plaintiffs filed suit); Lazy R Ranch, 511 S.W.3d at 542 (explaining defendant seeking summary 

judgment bore burden to establish that claims accrued “outside the limitations period”); Gonzales v. Sw. Olshan 

Found. Repair Co., 400 S.W.3d 52, 58 & n.13 (Tex. 2013) (holding evidence conclusively established that claims 

were “time barred because [claimant] brought them more than two years after discovering her injury,” even though 

the “record is not clear on what specific date” that occurred); Emerald Oil, 348 S.W.3d at 203 (holding cause of action 

accrued “by August 1991”). 
17 

“substantially interfere[d]” with those leases. Id. Regency argues that the court of appeals erred by 

applying this lease-by-lease analysis, and Swift does not disagree. We agree with Regency. 

In the first place, the migration of the injectate beneath a surface border into the subsurface 

space covered by one of Swift’s leases did not necessarily cause Swift to sustain a legal injury. As 

explained, a nuisance occurs when a condition “first ‘substantially interferes with the use and 

enjoyment of land by causing unreasonable discomfort or annoyance to persons of ordinary 

sensibilities,’” Town of Dish, 519 S.W.3d at 609, and a trespass to a mineral lessee’s nonpossessory property rights occurs when wrongful conduct first invades or interferes with the 

claimant’s legal rights to explore, obtain, produce, and possess the minerals, Lightning Oil, 520 

S.W.3d at 49. Because the surface owner, and not the mineral lessee, owns the possessory rights 

to the space under the property’s surface, id. at 47, the mere fact that contaminants have migrated 

into the subsurface space covered by a mineral lease does not itself establish that the lessee has 

sustained either of these legal injuries. 

But more importantly, as we have explained, Swift’s arguments in this Court do not require 

us to decide whether the single-action rule required Swift to bring all of its claims for all of its 

injuries to all of its interests under all of its leases in one single action or whether all of those 

claims accrued upon the occurrence of the first of those injuries.31 Because Swift relies solely on 

the general accrual rules and does not urge any exceptions, we do not consider whether the singleaction rule required Swift to bring all claims for all injuries to its interests under all of the leases 

31 Compare Emerald Oil, 348 S.W.3d at 207–08 (rejecting well-by-well accrual analysis when all damage to 

all wells was “caused by the same operator during the same period of time”), with Lazy R Ranch, 511 S.W.3d at 539, 

543–44 (holding claims alleging surface contamination at four discrete tank-battery sites on a 20,000-acre ranch 

accrued at different times, based on when the defendant’s conduct occurred). 
18 

in this one action, or whether these facts would trigger an exception (or justify recognizing a new 

exception) that would allow claim-splitting under these facts. Because Swift does not rely on the 

court of appeals’ lease-by-lease approach to accrual, we assume that all of Swift’s claims accrued 

when Regency’s wrongful conduct first caused Swift to sustain a legal injury. 

B. Pleadings and evidence 

Finally, we turn to the question of whether the pleadings and evidence conclusively 

established that Swift first sustained a legal injury on or before September 24, 2013. Consistent 

with the nature of limitations as an affirmative defense, Regency does not seriously contend that 

the evidence conclusively established that Swift sustained any legal injury, much less that it did so 

at any particular time. As Regency itself explains, it “has no interest in or desire to prove Swift 

suffered any legal injury or has any valid claim whatsoever.” Regency does point to evidence that 

it drilled the injection well in 2006 and publicly announced in 2007 that the injectate from the 

Tilden well would eventually extend underneath the Quintanilla Ranch, that it began injecting the 

injectate in 2007 and then increased the injection rate in February 2012, that hydrogen sulfide from 

its injection well was discovered at the Horton #1 well in August 2012, that to reach that well the 

injectate necessarily traveled somewhere within the Wilcox formation under the Quintanilla Ranch 

on which Swift maintains the mineral lease, and that modeling studies showed that the injectate 

likely crossed under the Quintanilla Ranch’s boundary as of early April 2009. 

But even taking all of this evidence as true, it does not conclusively establish that the 

injectate has substantially interfered with Swift’s use and enjoyment of its property interests, 

invaded or interfered with Swift’s rights to explore and produce minerals under its leases, or caused 

Swift any other legal injury, or when it might have done so. In fact, Regency disputes that the 
19 

injectate has caused Swift any such legal injury. As Regency notes, the evidence establishes that 

at this point experts cannot determine precisely where the plume exists or where it may be heading, 

much less when it arrived or may get there. We agree with Swift that at this point the evidence 

does not conclusively establish that a legal injury has occurred or when it may have done so. 

Regency also notes that when the contamination was discovered at the Horton #1 well in 

October 2012, Layline (the owner of that well) identified to Swift three of Swift’s wells that 

Layline thought were also affected, and Swift later claimed that two of those wells were in fact 

damaged by the injectate. But Layline actually only advised Swift that its wells “seem very near 

this injection well” and “could be affected,” and Swift identified the wells as damaged as of 

November 2015, not 2012. These facts and allegations do not conclusively establish that Swift 

sustained a legal injury before September 24, 2013. 

 Regency primarily relies not on the evidence but on Swift’s pleaded allegations, arguing 

the allegations themselves, or at least when combined with the evidence, establish that Swift 

sustained an alleged legal injury before September 24, 2013. We do not agree. 

In its plea in intervention, Swift based its claims on Regency’s alleged wrongful conduct 

consisting of “the manner in which” Regency operated the Tilden injection well, specifically by 

injecting the hydrogen-sulfide/carbon-dioxide mix into the Wilcox formation such that it reached 

and contaminated the Horton #1 well forty years before it should have. According to Swift, 

Regency’s conduct supports a trespass claim because Regency “willfully and intentionally 

continued to inject” the contaminants into the disposal well even though the injectate “is expanding 

at a much greater rate than [Regency] initially projected.” It also supports Swift’s negligence claim 

because Regency failed to “exercise the duty of due care to avoid degradation of Swift’s wells, 
20 

groundwater aquifers, and reserves.” This same alleged intentional and negligent conduct supports 

Regency’s claim for nuisance. And according to Swift, it supports a claim for gross negligence 

because Regency acted with “conscious indifference to the rights, safety, and welfare of others.” 

Swift alleged in its pleadings that this wrongful conduct had already caused (by the time 

Swift filed its plea in intervention on September 24, 2015) and would yet cause (at some time after 

that date) a variety of legal injuries. As to legal injuries Swift had sustained in the past, Swift 

alleged that the hydrocarbons subject to its mineral leases “are already imperiled,” and Regency’s 

revised modeling study showed that the injectate “has already reached an area in which Swift has 

proven undeveloped reserves (“PUDs”).” As a result, Swift alleged, it was already unable to 

“safely and economically develop these PUDs.” Regency’s conduct had created a nuisance 

because it had already “resulted in a condition that substantially interfered with Swift’s private use 

and enjoyment of its mineral interests.” And because Swift’s lease interests were “in the path” of 

the plume’s “inevitable expansion,” Swift was already “taking substantial preventative measures” 

to protect those interests. 

In addition, Swift alleged, Regency’s wrongful conduct would cause Swift to sustain future

legal injuries because the wells it had already drilled and the many it planned to drill on all of its 

leases were “located near” the injection well and “within the path of the accelerating” plume of 

contaminants. These contaminants, Swift alleged, were “expanding at an increased rate and pose 

significant and irreparable harm” to Swift’s “mineral interests and other rights to hydrocarbons 

and groundwater contained in reservoirs, formations, and aquifers in the [injectate’s] path.” As a 

result, any of Swift’s “existing or future wells that penetrate the Wilcox disposal zone will be 

subject to degradation and corrosion” and face “inevitable increased corrosion.” The contaminants 
21 

will “continue to expand” and will in the future “reach several more of Swift’s PUD locations.” 

Drilling the planned future wells will cost more to implement safety measures and protect 

equipment from corrosion and may be too dangerous or too expensive to drill at all. Swift’s 

interests in the groundwater aquifers “will be damaged” by the expanding plume, which will also 

“corrode and degrade Swift’s wellbore and pressure control devices,” “impair Swift’s hydrocarbon 

production,” contaminate Swift’s “hydrocarbon and water resources,” corrode “its production 

wells,” and cause “devaluation of its reserves.” In short, as to future injuries, Swift alleged it will 

be unable “to safely and economically develop these PUDs.” 

As a result of these past and future legal injuries, Swift alleged that it “has suffered and 

will continue to suffer damage to its property interests, including several PUDs in the area of the 

injectate,” resulting in monetary damages Swift later alleged total over $1 million. Swift alleged 

that its past damages included costs Swift had already incurred “related to investigation of 

enhanced safety measures to detect unsafe levels of [hydrogen sulfide],” periodic sampling of its 

well, and the then-present diminution in value of its PUDs. Future damages would result because 

Swift would have to drill future wells at “a much higher cost and risk” and possibly lose its drilling 

rights altogether, and its “inability to safely and economically develop these PUDs will have a 

significant economic impact on Swift.” Swift sought to recover “the value of the lost reserves, 

and/or the increased cost of drilling wells through” the Wilcox formation, as well as 

“reimbursement for any undiscovered damage caused to its [well] casing” as a result of the 

injectate and “the increased costs and expenses that it will incur in the future to plug and abandon 

the wells endangered by the injectate.” Swift also sought injunctive relief to prevent some of the 

future injuries and damages. 
22 

For purposes of determining whether Swift’s pleadings conclusively established that it 

suffered a legal injury on or before September 24, 2013, we need only consider the past legal 

injuries that Swift alleged. We conclude that the pleadings and evidence did not conclusively 

establish that Swift sustained a legal injury by that date. 

Swift did not allege that the injectate plume had already reached or damaged any of its 

existing wells or any of the specific sites where it planned to drill additional wells. But it clearly 

did allege that it had already suffered legal injuries before it filed its claims on September 24, 2015. 

Specifically, Swift alleged that because its interests were “in the path” of the expanding plume and 

that contamination was “inevitable,” its interests were “already imperiled,” it was already unable 

to “safely and economically develop these PUDs,” the migrating plume “substantially interfered” 

with its use and enjoyment of its mineral interests, and the value of its PUDs were already 

diminished. 

But its pleadings did not allege or establish when those past legal injuries occurred. In 

particular, Swift did not allege whether its past injuries occurred before September 24, 2013, or at 

some point between that date and the date Swift first filed its claims on September 24, 2015. The 

only allegation we have found that comes close to specifying a date by which an injury occurred 

is Swift’s allegation—apparently in support of its assertion that its mineral-lease interests were 

“already imperiled”—that Regency’s revised plume model showed that the injectate “has already 

reached an area in which Swift has proven undeveloped reserves.” This allegation apparently refers 

to a modeling study prepared by Dr. Liaqat Ali and presented at a Railroad Commission hearing 

in October 2013, which concluded that the injectate may have crossed under the Quintanilla 

Ranch’s boundary in April 2009. But the pleadings do not clearly and unequivocally allege 
23 

whether Swift’s interests became “imperiled” when the plume first crossed under the boundary 

and reached the PUD area or at some time thereafter. Wolf, 44 S.W.3d at 568 (noting that a judicial 

admission must be “clear and unequivocal” to have a “conclusive effect”). 

To be clear, the statute of limitations may very well bar Swift’s claims. At trial, or perhaps 

even on a subsequent summary-judgment motion after further pleadings and discovery, Regency 

may prevail on that point. Or it may be that Swift has yet to sustain any legal injury at all, and thus 

has no present right or authority to any legal relief. But at this point, the pleadings and evidence 

do not conclusively establish that Regency’s alleged wrongful operation of the Tilden injection 

well caused Swift to sustain a legal injury before September 24, 2013. 

V. 

Conclusion 

Because the pleadings and evidence do not conclusively establish that Regency’s alleged 

wrongful conduct caused Swift to sustain a legal injury before September 24, 2013, we conclude 

that Regency did not establish a right to summary judgment based on limitations. The court of 

appeals erred in holding that Regency is entitled to summary judgment on Swift’s claims for 

injuries to its interests in the PCQ lease. We reverse that part of the court of appeals’ judgment 

granting summary judgment and remand the case to the trial court for further proceedings. 

 

_____________________ 

Jeffrey S. Boyd 

Justice 

Opinion delivered: May 7, 2021