|aThe merits of this appeal in these consolidated cases relate to the interpretation of an oil royalty payment clause in an oil and gas lease. After rendering a partial summary judgment interpreting the clause, the district court signed an order of appeal and simultaneously issued a per curiam explaining why the district court declined to certify the judgment as final for purposes of an immediate appeal. After the record was lodged in this court, we issued, ex proprio motu, a rule for the parties to show cause by briefs why the instant appeal should not be dismissed as having been taken from a partial summary judgment without the proper designation of finality as required by La. C.C.P. art. 1915(B). For the following reasons, we do not reach the merits of the appeal, because we find that this court lacks appellate jurisdiction to review the partial summary judgment.
RELEVANT PROCEDURAL HISTORY
This litigation commenced as a concur-sus proceeding twenty-seven years ago, on August 24, 1984. Texas Gas Exploration Corporation (“Texas Gas”) named La-fourche Realty Company (“Lafourche Realty”) and the State Mineral Board of the State of Louisiana (“the State”) as defendants. The concursus proceeding involved multiple oil, gas, and mineral leases dating back to 1974, and the disputed ownership of land units in the Lake Enfermer Field (“the field”) in Lafourche Parish, Louisiana. A total of fourteen different lawsuits have been filed over the years since the litigation began. Some of the • lawsuits concerned the State and Lafourche Realty, but some involved other landowners. All fourteen lawsuits were eventually transferred and consolidated for trial; however, only four of the consolidated cases are at issue at this time (hereafter referred to as “the consolidated cases”).
As the successor-in-interest lessee, En-ergen was the designated operator for oil production under the Lafourche Realty leases, and was the appropriate party to pay and otherwise account for the royalties attributable to the leases for oil production from the field.
Lafourche Realty requested that the district court find all of the defendants in default of their obligations to pay royalties and in breach of their obligations to operate the leased properties for the mutual benefit of the lessees and Lafourche Realty. Lafourche Realty further requested that the district court order the defendants to render a full and complete accounting of the amount of oil produced, pay royalties calculated on the basis of all of the economic benefits attributed to the leases, pay damages plus attorney’s fees and costs, and order cancellation and rescission of the leases.
On May 27, 2010, fourteen years after Lafourche Realty asserted its claims regarding fraud and underpayment of royalties against Energen and the other co-defendants, Energen filed a motion for summary judgment, claiming that La-fourche Realty was precluded as a matter of law from the relief it sought in the litigation. Energen relied on the specific clause in the mineral leases that addressed the payment of oil royalties: “Lessee [En-ergen] may sell Lessor’s [Lafourche Realty’s] oil at the best market price obtainable and pay Lessor [Lafourche Realty] the price received f.o.b. the leased property.”
In Energen’s memorandum in support of its motion for summary judgment, En-ergen stated that it was “seeking dismissal of all claims by Lafourche Realty ... against Energen,” because Lafourche Realty’s claims contradicted the plain and unambiguous language of the leases. En-ergen maintained that “[s]ummary judgment is appropriate to ‘a particular issue’ or ‘theory of recovery,’ [pursuant to La. C.C.P. art.] 966(E).” In support of its motion, Energen filed deposition excerpts and an affidavit, along with authenticated copies of the leases and copies |6of Ener-gen’s contracts with its transporter. In opposition to Energen’s motion for summary judgment, Lafourche Realty offered affidavits and expert reports, all relating to Energen’s supposed efforts to hide the allegedly fraudulent marketing schemes from its royalty owners.
After a hearing, the district court granted Energen’s motion for summary judgment on November 30, 2010. The judgment dismissed Lafourche Realty’s cause of action, pursuant to La. R.S. 31:140, “asserting failure of the mineral lessee to make proper payment of royalties.” In written reasons for judgment, the district court emphasized that the summary judgment dismissed only one of Lafourche Re
On January 7, 2011, Lafourche Realty filed a motion for appeal or, alternatively, motion to certify the judgment as final for appeal. Energen opposed the motion, and the district court denied Lafourche Realty’s motion for appeal as |7premature on January 28, 2011.
On the same day that the district court granted Lafourche Realty’s second motion and order of appeal, February 3, 2011, the district court issued a per curiam, essentially adopting Energen’s opposing position that the November 30, 2010 judgment was not a final, appealable judgment. The district court stated:
The motion to grant an order for a devolutive appeal filed by [Lafourche Realty] on February 3, 2011[,] seeks to appeal a summary judgment granted pursuant to [La. C.C.P. art. 966(E),] and it is therefore not a final, appealable judgment. The [district] court does not determine and designate the summary judgment as a final judgment under the provisions of [La. C.C.P. art. 1915(B).] The [district] court cannot determine there is no just reason for delay due to the relationship between the adjudicated claim and the unadjudicated claim of [Lafourche Realty] asserting fraud by the mineral lessee in violation of the mineral lessee’s obligation to act as a reasonably prudent operator to market the crude oil for the mutual benefit of the mineral lessor and mineral lessee.
In its appellate brief filed in this court, Lafourche Realty assigns one error, asserting that the district court erred in granting summary judgment in favor of Energen, because the district court misin
LAW AND ANALYSIS
Appellate courts have the duty to examine subject matter jurisdiction sua sponte, even when the parties do not raise the issue. Motorola, Inc. v. Associated Indem. Corp., 2002-0716 (La.App. 1st Cir. 4/30/03), 867 So.2d 715, 717 (Motorola I). A final judgment of the district court may be appealed. See La. C.C.P. art. 2083. A judgment that determines the merits in whole or in part is a final judgment. La. C.C.P. art. 1841. Whether a partial final judgment is appealable is determined by examining the requirements of La. C.C.P. art. 1915. See La. C.C.P. art. 1911. It is appropriate for us to consider the basis for our jurisdiction before addressing the merits of this appeal. Motorola I, 867 So.2d at 717.
19Louisiana Code of Civil Procedure article 1915 authorizes the immediate appeal of partial final judgments, including partial summary judgments, with an appropriate designation by the district court.
In the per curiam simultaneously issued by the district court when the order of appeal was signed, the district court expressly determined that the No-vember 30, 2010 judgment was not a final, appealable judgment and refused to designate or certify the judgment as final, because it could not determine that there was no just reason for delay.
Both parties now maintain that the partial summary judgment, for all practical purposes, essentially resolved all issues between Lafourche Realty and Energen, even though no party was dismissed. Thus, the parties argue that the partial summary judgment is final and appealable pursuant to La. C.C.P. art. 1915(A), without the necessity of the district court’s designation of finality.
In the case sub judice, none of the parties in Lafourche Realty’s reconventional demands and/or petition for damages that were filed in the four consolidated cases are in a posture for dismissal, and none were dismissed. We disagree with the parties’ argument that the “practical effect” of the district court’s judgment is termination of all of Lafourche Realty’s claims against Energen. There is absolutely no indication in the record that the district court considered and/or dismissed all of Lafourche Realty’s claims against Energen. There is also no evidence that the parties indicated to the district court that the ruling on the partial summary judgment for the one cause of action would eliminate the need to litigate any more claims between Lafourche Realty and En-ergen.
Additionally, another notable flaw we have discovered with the November 30, 2010 judgment is that it is unclear whether all of the consolidated cases are 11Raffected by the district court’s ruling on the partial summary judgment.
Furthermore, we decline to convert the appeal of this non-final judgment to a supervisory writ, because to do so would be a blatant circumvention of the spirit of Article 1915, causing the delay and inefficiency which the codal provision obviously is designed to eliminate. See In re Chemical Release at Bogalusa, 98-1122 (La.App. 1st Cir.8/27/98), 718 So.2d 1015, 1016, writ granted, in part, 98-2505 (La.11/6/98), 726 So.2d 916. We believe that in cases like this one, where the district court makes an express determination that it cannot certify there is no just reason for delay for an immediate appeal, it is improper to review the merits of|14the uncertified partial summary judgment pursuant to our supervisory jurisdiction, thereby avoiding and/or ignoring the district court’s discretionary ruling on the certification. See In re Succession of Grimmett, 31,975 (La.App. 2d Cir.3/5/99), 738 So.2d 27, 31.
CONCLUSION
We find the November 30, 2010 judgment herein is a partial summary judgment that adjudicates fewer than all of the claims, was not designated as final by the district court in accordance with La. C.C.P. art. 1915(B)(1), and is not a |iafinal, appealable judgment. As such, the judgment may be revised at any time prior to rendition of the final judgment that adjudicates all the claims and rights and liabilities of all the parties, in accordance with La. C.C.P. art. 1915(B)(2). We further find that since Lafourche Realty’s recon-ventional demands and petition for damages are still pending in the consolidated cases, involving the same parties and similar facts and issues, we are without appellate jurisdiction to consider the appeal in these consolidated cases concerning the partial summary judgment. We therefore dismiss this matter, without prejudice, for lack of jurisdiction.
In order to avoid piecemeal litigation, this appeal in these consolidated cases is dismissed, ex propria motu, and this matter is remanded to the district court for an adjudication of the remaining issues. Appellate costs are equally assessed to La-fourche Realty Company and Energen Resources Corporation.
APPEAL DISMISSED WITHOUT PREJUDICE; REMANDED FOR FURTHER PROCEEDINGS.
. The lead docket number in the consolidated cases is 52468, which was consolidated with docket numbers 59436, 65168, and 79707.
. All issues in the consolidated cases that pertained to royalty payments for gas production were dismissed as prescribed on June 6, 2008.
. The district court determined that the partial summary judgment was not a final, ap-pealable judgment and that the motion for appeal was premature because Lafourche Realty had a pending motion for new trial. The motion for new trial was apparently untimely and was later withdrawn. Lafourche Realty then reurged its motion for appeal.
. We note that this position directly conflicts with the position Energen argued to the district court when opposing Lafourche Realty’s motion and order for appeal, and alternative motion for certification. At oral argument before this court, both parties indicated that they were now in agreement that the partial summary judgment was final and appealable; however, that assertion is insufficient for designation purposes under La. C.C.P. art. 1915. See Van ex rel White v. Davis, 2000-0206 (La.App. 1st Cir.2/16/01), 808 So.2d 478, 481 n. 2. Under the present and applicable version of Article 1915, the parties may not invoke this court’s appellate jurisdiction to review a partial summary judgment by mutual consent. Shapiro v. L & L Fetter, Inc., 2002-0933 (La.App. 1st Cir.2/14/03), 845 So.2d 406, 410. The jurisdiction of a court over the subject matter of an action or a proceeding cannot be conferred by consent of the parties. La. C.C.P. art. 3; Bennett v. Arkansas Blue Cross Blue Shield, 2005-1714 (La.App. 1st Cir.9/15/06), 943 So.2d 1124, 1127.
. Louisiana Code of Civil Procedure article 1915 provides as follows;
A. A final judgment may be rendered and signed by the court, even though it may not grant the successful party or parties all of the relief prayed for, or may not adjudicate all of the issues in the case, when the court:
(1) Dismisses the suit as to less than all of the parties, defendants, third party plaintiffs, third party defendants, or inter-venors.
(2) Grants a motion for judgment on the pleadings, as provided by Articles 965, 968, and 969.
(3) Grants a motion for summary judgment, as provided by Articles 966 through 969, but not including a summary judgment granted pursuant to Article 966(E).
(4) Signs a judgment on either the principal or incidental demand, when the two have been tried separately, as provided by Article 1038.
(5) Signs a judgment on the issue of liability when that issue has been tried separately by the court, or when, in a jury trial, the issue of liability has been tried before a jury and the issue of damages is to be tried before a different jury.*1060 tó) Imposes sanctions or disciplinary action pursuant to Article 191, 863 or 864 or Code of Evidence Article 510(G).
B. (1) When a court renders a partial judgment or partial summary judgment or sustains an exception in part, as to one or more but less than all of the claims, demands, issues, or theories, whether in an original demand, reconventional demand, cross-claim, third party claim, or intervention, the judgment shall not constitute a final judgment unless it is designated as a final judgment by the court after an express determination that there is no just reason for delay.
(2) In the absence of such a determination and designation, any order or decision which adjudicates fewer than all claims or the rights and liabilities of fewer than all the parties, shall not terminate the action as to any of the claims or parties and shall not constitute a final judgment for the purpose of an immediate appeal. Any such order or decision issued may be revised at any time prior to rendition of the judgment adjudicating all the claims and the rights and liabilities of all the parties.
C. If an appeal is taken from any judgment rendered under the provisions of this Article, the trial court shall retain jurisdiction to adjudicate the remaining issues in the case.
(Emphasis added.)
. Louisiana Code of Civil Procedure article 966(E) states in part, “A summary judgment may be rendered dispositive of a particular issue, theory of recovery, cause of action, or defense, in favor of one or more parties, even though the granting of the summary judgment does not dispose of the entire case[J” (Emphasis added.)
. A district court's mere signing of an order for appeal from a partial summary judgment does not constitute a proper designation and will not make that judgment immediately ap-pealable. In re Succession of Guilbeau, 2010-1200 (La.App. 3d Cir. 12/1/10), 51 So.3d 185, 187; City of New Orleans v. Howenstine, 98-2157 (La.App. 4th Cir.5/5/99), 737 So.2d 197, 199.
. In its per curiam, the district court provided reasons for not designating the partial summary judgment as final; therefore, we need not conduct a de novo review. Rather, the proper standard of review for certification decisions accompanied by the district court’s explicit reasons is whether the district court abused its discretion. See R.J. Messinger, Inc. v. Rosenblum, 2004-1664 (La.3/2/05), 894 So.2d 1113, 1122. See also Motorola, Inc. v. Associated Indem. Corp., 2002-1351 (La.App. 1st Cir. 10/22/03), 867 So.2d 723, 732-33.
. The remedy available to Lafourche Realty for immediate review of the partial summary judgment when the district court declined to certify it as final was to apply for a writ of review under this court’s supervisory jurisdiction. However, the record reflects, and the parties confirmed at oral argument before this court, that no such application was filed.
. See La. C.C.P. art. 1911, providing in part: “An appeal may be taken from a final judgment under Article 1915(A) without the judg-mentbeing so designated.”
. In contrast, an earlier judgment rendered by the district court when ruling on an exception of prescription was very specific as to which causes of action and which docket numbers in the consolidated cases were affected by the judgment.
. We also note that Lafourche Realty’s motion and order for appeal was not filed within the thirty-day time limit for a supervisory writ application. Thus, an application for supervisory writs would have been untimely. See Uniform Rules — Courts of Appeal, Rule 4-3.